Wayne Rooney equalled Sir Bobby Charlton's all-time goalscoring record for Manchester United to help Jose Mourinho's side to a 4-0 victory over Reading in the third round of the FA Cup this afternoon.

Rooney netted his 249th goal for the club to set United on their way to the fourth round, with further strikes from Anthony Martial and Marcus Rashford (2) wrapping up an eighth straight victory for the Red Devils.

United, who are now unbeaten in their last 25 FA Cup matches against second-tier opposition, immediately got into their stride and could have taken the lead after just 30 seconds when Rooney flicked the ball into the path of Rashford, who steered a measured finish just past the post.

The hosts were back on the attack moments later as Rooney latched on to a pinpoint pass from Marcos Rojo inside the area, but this time Ali Al-Habsi got down well to keep out the low finish.

Rooney would not be denied his historic moment for much longer, though, and his record-equalling 249th goal for United arrived in the seventh minute when he used his knee to steer Juan Mata's cross into the far corner.

Charlton was amongst the fans at Old Trafford to greet the achievement with a standing ovation, but it was quickly clear that United were not done for the day and they resumed their dominance immediately as Reading failed to slow down the early onslaught.

A deserved second goal arrived after 15 minutes when Martial played a one-two with Rooney before waltzing into the box without being challenged and passing his finish into the bottom far corner.

An overawed Reading, managed by Jaap Stam on his return to Old Trafford, failed to learn from that mistake and Martial was again allowed to dribble into a shooting position soon after, but this time Al-Habsi was able to collect his shot at the second time of asking.

The visitors finally created a decent sight of goal after 25 minutes when Joey van den Berg was picked out by a corner on the edge of the box and volleyed the ball back into a dangerous area, but Liam Moore could not get the touch to flick it home from close range.

United were immediately back on the attack themselves and it should have been 3-0 moments later when Rashford raced on to a Chris Smalling through-ball before rounding the keeper, only to put his finish into the side-netting with the goal gaping.

The youngster then flashed another effort wide from range before finding himself in on goal once again, but this time Al-Habsi stood tall to stop his shot.

The hosts made a renewed push for the third goal in the closing stages of the first half as Mata was thwarted by George Evans and curled an effort high and wide, before Chris Gunter did just enough to prevent Martial from turning Rashford's low cross in at the front post.

Reading held the deficit to just two goals at half time, but they were soon back under the cosh after the restart and Rooney was just short of connecting with a Rashford cross at the back post in the opening minutes of the second half.

Michael Carrick was the next to come close for the home side when he tried to curl a low effort into the bottom corner from range, but Al-Habsi was across to turn the ball away well.

The Reading keeper almost gifted United a third goal 10 minutes into the second half when he spilled Marouane Fellaini's low cross at the feet of the outright record-chasing Rooney, but Al-Habsi redeemed himself by denying the England skipper from point-blank range.

The hosts did finally kill the game off once and for all with 15 minutes remaining when Carrick slid an incisive pass through for Rashford, who kept his composure to tuck a finish past the keeper for his first goal since September.

Having waited 18 games for one, a second arrived just four minutes later for Rashford as he hammered the ball into an empty net from a yard out after a calamitous error from Al-Habsi had put it on a plate for the United youngster.

A fifth goal would not have flattered Mourinho's men, and they almost found it in the closing stages when first Rooney and then Fellaini were denied by Al-Habsi, who went some way to atoning for his earlier mistake by keeping the Belgian at bay from close range.

It was only damage limitation by that point, though, as United coasted into the fourth round with an eighth consecutive victory in all competitions - their best run of form since 2009.

Mourinho's side will now turn their attention to an EFL Cup semi-final against Hull City on Tuesday before hosting arch-rivals Liverpool at Old Trafford next weekend, while Reading are next in action against Queens Park Rangers on Thursday.