|Berbatov's hat-trick added to the three he scored against Liverpool and five against Blackburn this season [Reuters]
Dimitar Berbatov scored his third hat-trick of the season as English Premier League leaders Manchester United maintained their unbeaten league record with a 5-0 hammering of Birmingham City.
Robin van Persie also scored three as a 3-0 win over Wigan Athletic moved Arsenal into second place, above Manchester City who fell behind when they lost 1-0 to Aston Villa in Saturday's evening kickoff
Striker Darren Bent, who joined Aston Villa for a club record fee of $28.62 million this week, scored the winner after 18 minutes of his debut against City.
The England international, who joined Villa from Sunderland on Tuesday, swept the ball home from six metres out after City goalkeeper Joe Hart could only push Ashley Young's shot into his path.
Fifth-placed Tottenham Hotspur lost ground on the leaders after drawing 1-1 at Newcastle United where Fabricio Colocinni scored for the home side and Aaron Lennon equalised in stoppage time.
West Ham United looked as though they had climbed out of the relegation zone, leading 2-1 at Everton going into stoppage time, before Marouane Fellaini equalised for the hosts.
Liverpool gave Kenny Dalglish his first win since he returned as manager with a 3-0 victory at Wolverhampton Wanderers in the early kickoff.
"We might not be smashing people across the nose with their elbows, but we'll always be competitive," Dalglish told Sky Sports after Liverpool's second away win of the season in the Premier League.
"The way we worked was great credit to them, we are one unit, there are no divisions in this football club and if we stick together we've got a chance."
A double from Fernando Torres and an excellent strike from Raul Meireles secured Dalglish his first win in four games and inched Liverpool away from the bottom three and increased Mick McCarthy's own fears of the drop.
Spain international Torres displayed glimpses of his old self, collecting his 10th and 11th goals of the season from close range while Portugal midfielder Meireles is beginning to look the player that was pursued so vigorously by previous manager Roy Hodgson.
Dalglish still went into this game having made the worst start by a Liverpool manager since Roy Evans failed to win any of his first three matches in 1994.
It would have been the longest winless run since George Patterson 83 years ago, but Torres eased nerves when he scored eight minutes before half time.
Meireles was played onside by Ronald Zubar and his pass into the area
presented Torres with a simple finish, his third goal of 2011.
Wayne Hennessey was required to deny Dirk Kuyt early in the second period but barely 60 seconds later he was powerless to prevent Meireles killing off the game.
There appeared to be no danger when Christophe Berra headed a hopeful cross out of the area until Meireles unleashed a dipping volley from 25 yards that looped over Hennessey and into the top corner.
Kuyt broke into the area in injury time and set up Torres for another simple finish.
At Old Trafford, Berbatov started the rout inside two minutes after Nani won a corner inside the first 60 seconds and Ryan Giggs curled in a superb cross from the right-hand flag.
John O'Shea steered a strong header towards the far corner where the Bulgarian forward headed into the back of the net from a position practically on the goal-line.
The Bulgarian, whose hat-trick adds to his three goals against Liverpool and five against Blackburn, claimed a second goal just after the half-hour when Birmingham defender Roger Johnson carelessly conceded possession just inside his own half and Berbatov finished a swift attack started by Wayne Rooney.
Just before half time Berbatov made a one-two with Rooney, who sent over a perfectly-weighted far-post cross which Giggs, arriving at pace, placed first-time into the back of the net.
In the second half Rooney's pass allowed Giggs to deliver a pinpoint cross from the left which Berbatov met with an accomplished finish into the roof of the goal from six yards.
The relentless United pressure seemed likely to yield more goals and, after failing with a number of efforts from distance, Nani collected O'Shea's 75th minute pass and finished clinically.