Yatabare thought that he had snatched a winner in stoppage time, but he had the goal ruled out for offside.
Read how all the action unfolded below:
Good evening! Mali and Cameroon are the final two nations to begin their campaign, and are just half an hour away from kickoff. Let's take a look at the team news.
MALI STARTING XI: Soumaila Diakite, Tamboura, Coulibaly, Drissa Diakite, Wague, Sylla, Sako, Keita, Sambou Yatabare, D'Diaye, Mustapha Yatabare
CAMEROON STARTING XI: Ondoa, N'Koulou, Oyongo, Choupo-Moting, Chedjou, Loe, Aboubakar, Salli, Bedimo, Enoh, Moukandjo
Cameroon are missing recently-appointed captain Stephane Mbia as he is suspended following his sending off in their qualifier against Ivory Coast in November. Maxim Choupo-Moting takes the armband in his absence.
Mali are without Cheick Diabate for this tournament, as the formidable striker underwent knee surgery just a couple of weeks ago. Modibo Maigi will lead the attack with assistance from Mustapha Yatabare and Seydou Keita, who is competing in his seventh Africa Cup of Nations. The Roma midfielder has scored seven goals in the last three competitions from 22 shots.
Cameroon's World Cup campaign in the summer was something of a disaster, with fights between players and the the team losing all three of their group games. However, coach Volke Finke insists that that is behind the team: "I really think the spirit, the mentality has changed. The last two or three months there has been a closed dressing room. Good work starts from there. Nothing has leaked out of the dressing room. The group is united and all working together. We are just working towards the future. I know what was going on and this is why we always pay attention to make sure we keep going in the same direction."
Meanwhile, Mali coach Henryk Kasperczak told reporters: "Cameroon are experiencing a transition phase with a new generation of players as Mali are. Even if the two teams appear as favourites, all the fixtures in this group will be crucial to qualify to the quarter-finals."
The other two teams in this group, Ivory Coast and Guinea, have already played this afternoon, and the match ended in a 1-1 draw, with the Ivory Coast finishing the match with 10 men. Both of these sides know that a win here will move them to the top of the table.
The players are starting to make their way out for the match. Both sides seem to have plenty of support in the stadium, which is absolutely packed. While Equatorial Guinea may not boast the biggest stadiums in the world, they've been selling out the seats so far in this tournament.
Mali's preparations have been a little difficult. They arrived in Equatorial Guinea last week, but their training equipment only turned up on Saturday, so it will be interesting to see how well prepared they are.
PREDICTION! Just moments before kickoff it's time for a quick prediction. Cameroon have turned things around since their troublesome World Cup campaign, and are one of the favourites for this tournament with an exciting young squad. I think they'll come away with a 2-1 win this evening.
KICKOFF! Cameroon get the match underway.
There's an early chance for Cameroon as Eyong Enoh wins a free kick near the wing, It's curled in, but Salif Coulibaly quickly gets it clear for Mali.
Ambroise Oyongo gets forward for Cameroon, but the defender is quickly challenged from Drissa Diakite to ensure that the Cameroon man does not get his cross in. Cameroon are dictating the pace at the minute.
Wolves winger Bakary Sako gets Mali down the other for the first time, tearing down the left flank before trying to get a cross in, but his ball is put behind for a corner, which N'Koulou easily clears.
There's an injury concern for Cameroon as Henri Benimo appears to have injured his leg while landing awkwardly following a challenge from Molla Wague. It wasn't a bad tackle by any means, but he did seem to twist his lower leg awkwardly as his slid to the ground.
Sako makes another good run down the wing in a bid to create something for Mali, and once again his ball towards the box is put behind for a corner, but the ball swings out of play as the winger tries to curl it in from the set piece.
CHANCE! Joseph Ondoa has to make the first save of the game as Sako picks out Mustapha Yatabare with a superb swinging cross, but the keeper gets his fingertips to it to put it behind.
CHANCE! Sako and Yatabare team up again as the corner is initially cleared, but Sako picks the striker out with a well-placed ball, which deceives the Cameroon keeper, but Yatabare's header is a fraction wide.
There's a bit of confusion as there are more injury problems for Cameroon as Eyong Enoh and Vincent Aboubakar are both limping, while Franck Kom appeared to be getting ready to come on as Bedimo continues to struggle, but the midfielder eventually sits back down, so whoever he was preparing to replace is obviously trying to push through.
Sako and Tamoura link up near the corner flag, but the latter's cross fails to find any of his Mali teammates, and Cameroon go on the counter-attack. It's certainly been a lively start to the match.
SUB! Cameroon are forced to make a chance, and it's Eyong Enoh who has to make way, with Franck Kom coming on in his place. Aboubakar and Bedimo are still limping though, so that might not be the only substitution we see before half time.
Aboubakar shakes off his injury concern to make a superb run into the box, but Tamboura times his challenge superbly to prevent the midfielder getting his shot away. He has another chance moments later, but Diakite manages to tip it behind for a corner. This is the first time Cameroon have really threatened, and it looks like the forwards are working well together.
Mali are back on the attack as Sako and Tamboura both try to send in crosses from the left, but their efforts fail to find their teammates in the middle.
BOOKING! Mamoutou N'Diaye is the first player to be shown the yellow card this evening as he bundles down Enoh around 30 yards out. Cameroon get a free kick as well as a result, but Yatabare is back to make the clearance.
Sako has been absolutely superb for Mali so far this evening, and he makes another run at the Cameroon defence, attempting to slice the ball in from a tight angle, but the keeper is there to make to stop.
Mali are dominating possession at the minute, and are getting the ball forward well. The problem is that they don't have too many options in the middle, with Sako relying on Yatabare to be there when he looks to cross it in. Mali need to get numbers forward if they want to really stretch the Cameroon keeper.
Once again, Yatabare is the only one there as Sylla sends the high ball forward. His brother, Sambou Yatabare, was arriving, but he took the shot on himself and won the corner. Ondoa came off his line to try and punch the set piece clear, but he was fouled, ending the Mali threat.
Mustapha Yatabare thinks he's through on goal, but he's flagged offside as he gets his shot away. Ondoa appeared to have to covered though.
N'Diaye is living dangerously as he brings down Choupo-Moting. The Mali man has already been booked, but the referee just awards the free kick. He'll have to be careful is he wants to see out the match.
CHANCE! Choupo-Moting whips the ball in towards Benjamin Moukandjo, who hasn't had a lot to do so far. The striker rises up high to try and head in, but Tamboura defends well to force him to nod it wide.
Cameroon quickly win another free kick as they push for a gal just before half time. Choupo-Moting's header is weak though, and goes wide of the upright.
Cameroon have seen the majority of the ball in the last five minutes, but their chances have been pretty limited.
HALF TIME: Mali 0-0 Cameroon
So it's all square at half time after an open but goalless first 45 minutes. Mali had the better of the chances, but Cameroon looked stronger towards the end of the half.
Cameroon had slightly more possession over the course of the 45 minutes with 56% of the ball. Mali had more shots though, two of which were on target compared to just one for Cameroon.
No matches have finished goalless in this year's Africa Cup of Nations so far, so the chances of a second half goal seem high. Mali certainly looks the more likely in the first half, but it's too soon to right off Cameroon.
The players are starting to make their way back out for the second half.
KICKOFF! Mali get the second half underway, with neither side making any chances during the interval.
CHANCE! Vincent Aboubakar tries to break the deadlock just moments after the restart with a curling effort from 25 yards out, but his effort swerves just wide.
CHANCE! Cameroon continue to press at the start of this second half, and win a free kick 25 yards out. Moukandjo curls it in towards Aboubakar, but he couldn't quite get his head to it.
Seydou Keita was kept pretty quiet in the first half by his standards in recent AFCON history. He tries to get Mustapha Yatabare involved up front, but Oyongo forces the midfielder to put it out for a Cameroon throw.
The excitement of the first half hasn't really been matched so far in the second half, as both sides look a little more defensive, as they're probably more concerned with not falling behind early on in the second half. If the stalemate continues much longer though, it wouldn't be a surprise to see some substitutions being made.
Edgar Salli makes a quick burst towards the Mali goal, but he's tripped just outside the box, giving Cameroon a free kick in a dangerous position.
Moukandjo and Chedjou appear to get a bit mixed up during the free kick. The striker fakes a run at the ball, and the defender is slow to react before firing the ball well high.
Mali finally have a chance down the other end in this second half as Yatabare is brought down, but Keita's free kick into the penalty area fails to find any of his teammates.
There's an injury concern for Mali now as Tamboura, who has been superb at both ends of the pitch, is tripped by Raoul Loe, and he appears to have pulled something in his groin.
Tamboura limps to the sidelines as the Mali substitutes start warming up. It looks like the defender could be heading off.
Eventually, Mali are able to take the free kick following the foul on Tamboura, but Keita's cross into the box if watched carefully by Ondoa, and the keeper comes off his line to take it effortlessly.
GOAL! Mali 1-0 Cameroon (Sambou Yatabare)
The younger of the two Yatabare brothers gives Mali the lead as Keita bursts into the box and plays it forward for the striker, who takes a touch before slicing it in from out wide. He's been pretty quiet this evening, with Mustapha Yatabare getting most of the chances, but he certainly made the most of it when the ball fell to him.
Sako has been quiet in the second half after an impressive opening 45 minutes, but he gets involved again as he tries to set up a second for Mali, but he tangles with N'Koulou on the edge of the box, and it's the defender who gets the decision.
Cameroon are pushing to get back on level terms, but N'Koulou's ball into the box goes straight to Soumaila Diakite before the forwards can reach it.
SUB! Cameroon make their second change, and it's first-half substitute Franck Kom who makes way for Etoundi Franck. To be fair, Kom has been completely anonymous since coming off the bench.
SUB! Mamoutou N'Diaye, who had looked destined for a sending off after some rash first-half challenges, is the first Mali player to be withdrawn as Tongo Doumbia replaces him in midfield.
Diakite has to come off his line to punch the ball clear as Etoundi pushes forward, but the keeper beats the substitute to the ball.
GOAL! Mali 1-1 Cameroon (Ambroise Oyongo)
Cameroon get the equaliser they're been pushing for through the unlikely source of Ambroise Oyongo. The defender times his slanting run towards the goal to perfection, taking a touch to round Diakite before tapping Moukandjo's delivery into the back of the net. That's the defender's first international goal.
SUB! Mali react, sending Modibo Maigi on in place of Mustapha Yatabare to give them some fresh legs up front.
In the run up to the goal, there was a clash between Yacouba Sylla and Vincent Aboubakar, which appeared to finish with the Cameroon striker making contact with his head, but the Mali man overplays his reaction, and fails to get any sympathy from the referee.
Sylla is involved again as Etoundi trips the Cameroon midfielder around 30 yards out, giving Mali a free kick in a promising position as the game heads into four minutes of stoppage time.
DISALLOWED GOAL! Mali think they've won it as Keita curls the ball in and Ondoa parries it into the path of Sambou Yatabare, but the scorer of the first goal was a fraction offside, ruling out the tap in.
OFFSIDE! There's another chance down the other end as Etoundi is through on goal, but he's tripped by the keeper. He looks around looking for a penalty, but instead sees the referee pointing to the assistant, who had raised the flag for offside.
FULL TIME: Mali 1-1 Cameroon
Some late drama as both sides come close to snatching a win in stoppage time, but the game finishes level after Ambroise Oyongo cancelled out Sambou Yatabare's effort.
With the other match in Group D also finishing 1-1 earlier, it ensures that all sides are level in the table after the first round of fixtures.
Well that's all from this match, but join us again tomorrow when the second set of group matches get underway, with the teams from Group A in action. Until then, thanks for joining me this evening. Goodbye.