In his final appearance against his club’s eternal foes before leaving for the Los Angeles Galaxy, Liverpool captain Gerrard came on at half-time, only to be sent off after 43 seconds for a crude stamp on Ander Herrera, who had created Mata’s 14th-minute opener.
Mata added a glorious, volleyed second goal and despite Daniel Sturridge’s reply and Wayne Rooney seeing a late penalty saved, United held on to condemn Liverpool to a first league defeat since their 3-0 loss at Old Trafford in December’s reverse fixture.
Liverpool’s run of 13 games without defeat had given them an opportunity to knock United out of the Champions League places, but instead Louis van Gaal’s side remain fourth, a healthy five points above their rivals with eight games of the season remaining.
Gerrard’s moment of madness proved the game’s major talking point, but there was no disguising United’s superiority as they confirmed the return to form sparked by last weekend’s 3-0 defeat of Tottenham Hotspur.
After a fourth consecutive league win — and only a second success at Anfield in eight visits — United will now anticipate forthcoming games against Aston Villa, Manchester City and Chelsea with something approaching the confidence of old.
Brendan Rodgers’s Liverpool players, meanwhile, head into the international break hoping to find a second wind when they return.
With Pele and United greats Alex Ferguson and Bobby Charlton in the directors’ box, there was no shortage of football royalty in attendance as the two teams — both unchanged — took to the field beneath warm spring sunshine.
Visiting goalkeeper David de Gea had to slide out and foil Raheem Sterling early on, but it was United who took control, patiently stringing passes together in defence and probing for gaps in a Liverpool side who displayed uncharacteristic carelessness with the ball.
– Herrera supplies spark –
Following a spell of possession, Herrera created the opener with a fine, piercing through ball to his Spanish compatriot Mata, who assuredly found the bottom-left corner with his weaker right foot.
By way of response, Sturridge lashed an audacious volley wide from Jordan Henderson’s lofted pass, but with the United supporters behind De Gea’s goal in full, crowing voice, the home side seemed cowed.
It was not until 10 minutes before half-time that Liverpool created a chance of note, but when Jordan Henderson’s superb right-wing cross was teed up for Adam Lallana by Sturridge, the former Southampton man could only shoot wide with De Gea rooted to the spot.
Rodgers took decisive action at half-time by introducing Gerrard in place of Lallana, but it was a move that would back-fire spectacularly.
Seconds after coming on, Gerrard clattered into Mata and when Herrera then returned the favour, the Liverpool skipper reacted with a crude stamp on his opponent’s left calf that left referee Martin Atkinson with no option but to send him off.
Philippe Coutinho attempted to sound the revolt, shooting narrowly over from what has become trademark long range, but just before the hour, United doubled their lead with a sumptuous goal.
Four minutes after replacing Ashley Young, Angel di Maria clipped a pass into the box to Mata, who catapulted a sensational scissors kick past Simon Mignolet.
There seemed no way back for the home side, but 10 minutes later Coutinho freed Sturridge with a pass down the inside-right channel and the England striker rattled a right-foot shot inside De Gea’s near post.
After Emre Can was harshly adjudged to have bundled Daley Blind to the ground, Rooney saw his spot-kick parried by Mignolet, but it was United’s day and Liverpool’s match ended on a sour note with Martin Skrtel appearing to stamp on De Gea as he chased a through ball.