Cristiano Ronaldo has warned his Real Madrid teammates that they must 'remain calm' after opening up a 3-1 lead against Paris Saint-Germain at the halfway stage of their Champions League clash.

Back-to-back winners Madrid recovered from behind to take a two-goal advantage with them to the Parc des Princes for the second leg of the last-16 tie.

Ronaldo scored two of Los Blancos' goals and full-back Marcelo popped up in the box late on to add a potentially killer third, though the Portuguese superstar is cautious of what is to come in Paris on March 6.

"The fans have helped us a lot and we felt their warmth. It has to be that way," he told reporters at full time. "Marcelo's goal was very important, he played a good match and he deserved it.

"When goals are scored and your team wins, it is always special. Today it started and I scored two. The tie is not over yet. We have to go to Paris to win and to score goals, to be calm and to qualify for the next phase.

"This was an important victory. We started the match well, but we let in a goal. But this is the Champions League and Madrid have the experience. Games last 90 minutes and, at home, we wanted to play a good game. We have a good advantage for the return thanks to those two late goals.

"We knew [PSG] were a very dangerous team with the forwards they have. We knew we had to press them to win the ball. In the second half we waited a little bit, we played better, and we had more opportunities."

Ronaldo took his personal Champions League goals tally for Madrid to 101 with his first-leg brace against PSG.