- Record signing Juan Mata makes Man Utd debut and departs to standing ovation
- United beat Cardiff City 2-0 as Van Persie marks return from injury with early goal
- Arsenal stumble at Southampton to allow Man City the chance to go top of the Premier League
- Liverpool thrash Everton 4-0 thanks to goals from Sturridge (2), Suarez and Gerrard
Manchester United's record signing Juan Mata made a winning start to his Old Trafford career on a night when Arsenal's Premier League ambitions encountered a setback.
The Spaniard played 85 minutes of United's 2-0 victory over Cardiff City before being substituted to a standing ovation following a promising debut.
"It was a very special day for me. My first game -- my debut -- with a victory. It was perfect. I enjoyed it a lot," Mata told Manchester United's in-house media company MUTV.
"What I love most is to play. So these minutes [on the pitch] are very important. Now I'm going to train and I'm looking forward to playing at the weekend and trying to do my best for the team."
Signed for a club record $61 million, Mata -- who trained with his new team-mates for the first time on Monday following his move from Chelsea -- had a hand in United's opening goal.
It came as he swept a diagonal ball out to Ashley Young, whose cross was eventually turned in by Robin van Persie after Antonio Valencia's header hit the crossbar.
The Dutchman had needed just six minutes to score after making his first start since December 10 following a thigh problem.
Young doubled the lead in the second half as United ensured that the return of 1999 Champions League winning legend Ole Gunnar Solskjaer, now in charge of Cardiff, to Old Trafford was not a happy one.
United's victory enabled them to close the gap on sixth-placed Everton, who were thumped 4-0 by city rivals Liverpool as Daniel Sturridge (2), Luis Suarez and Steven Gerrard gave the home fans a night to remember.
The misery for Blues boss Roberto Martinez was compounded when Romelu Lukaku was forced off the field on a stretcher after a worrying injury to his ankle.
Another manager who may be feeling a little unease is Arsene Wenger, whose Arsenal side lost two potentially crucial points at Southampton in a 2-2 draw.
The Gunners' coach was held up in traffic ahead of the game and the team also struggled to go through the gears, trailing 1-0 at halftime following a lackluster 45 minutes.
Goals from Olivier Giroud and Santi Cazorla turned the game on its head, but Adam Lallana replied for the hosts to ensure that the match finished 2-2.
Arsenal still lead the Premier League but the draw means second-placed Manchester City can climb above them should Manuel Pellegrini's free-scoring side win at Tottenham Hotspur on Wednesday.
Chelsea can also climb above Arsenal on Wednesday, should Jose Mourinho's side beat West Ham at home by more than two goals.
In Tuesday's other games, Swansea and Crystal Palace recorded much-needed wins -- at home to Fulham (2-0) and Hull (1-0) respectively -- while Norwich hosted Newcastle in a goalless encounter that featured a red card apiece for both sides.