London: Wayne Rooney struck a second-half hat-trick as Manchester United came from two goals down to beat West Ham 4-2 and strengthen their position at the top of the English Premier League.
Mark Noble had struck two penalties for the hosts at Upton Park but also felt Nemanja Vidic should have been dismissed by referee Lee Mason for denying Demba Ba a goalscoring opportunity.
United took full advantage in the second half, with Rooney pulling a goal back before levelling with his 100th league goal for his club.
The England striker then established a lead with a penalty after Matthew Upson’s handball, before Javier Hernandez grabbed another.
United manager Sir Alex Ferguson watched the match unfold from the stands as he is serving a touchline ban for criticising referee Martin Atkinson.
After 10 minutes another decision went against his team when the hosts took the lead through Noble’s first penalty, after a move that started on the edge of West Ham’s penalty area.
Thomas Hitzlsperger’s long pass out of defence released Carlton Cole, whose attempt to lob the ball over Patrice Evra resulted in the France international handling.
Noble kept his nerve and sent Tomasz Kuszczak the wrong way to establish a lead, then doubled the advantage in the 25th minute with another spot-kick.
Mason's decision for the second penalty may have angered Ferguson, as Vidic was certain his challenge on Cole came outside the area.
The Serbia international even pointed to the precise area he had made the tackle as Cole danced in from the left, but Mason had already made his decision.
Noble went for power with his second penalty, and in the opposite corner, with his finish angling into the roof of the net.
United were inevitably going to see more of the ball as they chased the game, but their first sight of goal led to an athletic save from Robert Green.
West Ham manager Avram Grant could not understand why Green did not play for England against Ghana in Tuesday’s friendly at Wembley following his recent good form.
He produced a fine stop to deny Park Ji-Sung when the midfielder was left unmarked and unleashed a powerful volley.
United also felt they should have had a penalty when Rooney’s poor control saw the ball flick up and strike Upson on the arm.
Vidic, though, was thankful for Mason's leniency when he was only given a yellow card when he prevented Ba from racing through on goal. Hitzlsperger flashed the resulting free-kick just wide.
Hernandez was brought on at the half-time interval, with Ryan Giggs moved to left-back as United looked to get back into the game.
Rooney pulled a goal back with a spectacular curling free-kick 25 yards from goal after Noble had fouled Michael Carrick in the 65th minute, giving United momentum heading into the final phase of the game.
Rooney then levelled the match when he collected Antonio Valencia’s pass, raced past Manuel Da Costa and fired his finish beyond Green.
Dimitar Berbatov, on as a substitute, forced two saves from Green but it was Rooney who grabbed the lead for them, tucking away his penalty after Upson handled Fabio da Silva‘s cross.
Giggs crossed for Hernandez to tap in with six minutes remaining to add gloss to the scoreline.