WAYNE Rooney equalled Sir Bobby Charlton's all-time goalscoring record as Manchester United cruised into the FA Cup fourth round at the expense of Reading.

The England striker notched his 249th goal in all competitions when he fired the Red Devils into a seventh-minute lead.

Anthony Martial added a second in the 15th minute and Marcus Rashford notched a late three-minute brace from which there was no coming back for the Royals on a disappointing return to Old Trafford for boss Jaap Stam.

Reading may be riding high in the Championship, but there was a massive gulf in class between themselves and Mourinho's star-studded team.

Yes, Stam's men deserve credit for their toil and endeavour throughout the 90 minutes.

But they were made to look second best all over the pitch and were totally outclassed in midfield as their search for a first-ever victory at Old Trafford continues.

Stam made two changes from the Monday's incredible 3-2 comeback victory at Bristol City, with George Evans and Liam Kelly both recalled.

Evans was brought in to do the defensive midfield job of Joey van den Berg, who was forced to drop into central defence in place of injured skipper Paul McShane.

Meanwhile, Mourinho made nine changes but, with an abundance of riches at his disposal, he could still name a strong team loaded with attacking options in the form of Wayne Rooney, Juan Mata, Anthony Martial and Marcus Rashford, with Zlatan Ibrahimovic, Paul Pogba and Henrikh Mkhitaryan providing assurance from the bench.

The home side's intentions were clear form the first whistle, and they went close with just 40 seconds gone when Rashford ran at a back-tracking defence but missed the target from 18 yards.

Then in the second minute Ali Al-Habsi came to Royals' rescue with a smart one-handed save to deny Rooney on the angle.

But Reading's resistance was broken in the seventh minute by Rooney.

Martial drifted past Chris Gunter and Garath McCleary before finding Juan Mata who whipped in an inviting left-wing cross which Rooney volleyed past Al-Habsi from eight yards out for his record-equalling goal.

It was the worst possible start for Stam's men – and, after Michael Carrick had fired wide from 18 yards – it got even worse when United doubled their lead in the 15th minute.

Again, Reading's defence was all at season when Martial played a neat one-two with Rooney before sliding the ball past Al-Habsi and into the far corner.

Reading simply could not contain the star-studded Red Devils, although the home side suffered a blow when Marcos Rojo limped off with an injury to be replaced by Phil Jones.

It did little to check United's momentum and it needed a quality save from Al-Habsi to prevent Martial from scoring again in the 23rd minute.

Royals hit back two minutes later when Liam Moore was an inch away from turning in van den Berg's volley from a Garath McCleary corner.

Back, though, came United and they almost grabbed a third on 27 minutes when Rashford collected Chris Smalling's pass and rounded Al-Habsi, only to shoot into the side netting to the visitors' relief.

The United youngster also failed to beat Al-Habsi when one-on-one a couple of minutes later.

Reading tried to build some momentum of their own, but they were being over-run in midfield and struggled to keep possession.

If anything they were fortunate to be only 2-0 down at the break, such was United superiority all over the pitch.

Stam attempted to stem the endless tide of United attacks by sending on Jordan Obita for the second half in place of ex-United defender Tyler Blackett.

But it was the home side who threatened first after the restart, Michael Carrick testing Al-Habsi with a curling effort from 25 yards.

And they almost scored a third in the 56th minute when Al-Habsi spilled a Marouane Fellani cross before making amends by saving Rooney's follow-up with his leg.

Stam had little choice but to go for broke and send on John Swift for George Evans with a little over 30 minutes to go.

It led to decent spell for the visitors as a stinging effort from Yann Kermorgant was blocked inside the United box midway through the second period.

But as they pushed men forward they were exposed at the back, and were punished again with 15 minutes to go when Rashford collected Carrick's pass on the left before racing into the box and slotting into the far corner.

Al-Habsi could do little about that one, but he had a moment to forget when he gifted United their fourth just three minutes later.

The Oman stopper took his eye off the ball as he collected Moore's back-pass and missed his kick completely, presenting Rashford with the easiest of tap-ins into an empty net.

Al-Habsi atoned for his mistake with a superb one-handed save from Fellaini, but the damage had already been done.

Nobody was more aware of the task facing Royals than Stam himself. But the Dutchman – whose name was sung throughout the game by United fans – cannot have expected his side to surrender so meekly, albeit against a team of United unquestionable quality.

Reading return to Championship action next Thursday when they host QPR (8pm ko).