Sir Alex Ferguson's final match in charge of Manchester United saw his side throw away a 5-2 advantage as West Bromwich Albion battled back to claim a share of the spoils in a 10-goal Premier League encounter this afternoon.
Visiting United dominated the first half at The Hawthorns and went on to score three goals within the opening 30 minutes.
First Javier Hernandez picked out an unmarked Shinji Kagawa inside the West Brom area in the sixth minute and the Japanese international sent a downward header beyond the reach of Ben Foster, before Jonas Olsson put through his own net from an Antonio Valencia cross three minutes later.
Then with 30 minutes played, full-back Alexander Buttner scored his second goal of the season when he drilled a shot inside Foster's far post following a through-ball from Tom Cleverley.
However, despite the fact that they had been dominated for most of the half, the Baggies gave themselves a lifeline in the closing stages when James Morrison fired in a low shot five minutes before the break.
Morrison's goal appeared to have given the home team some impetus at the start of the second half and five minutes in, substitute Romelu Lukaku reduced the arrears further when he beat Anders Lindegaard with a curling effort from outside the area.
In their very next attack, though, United restored their two-goal advantage. Valencia cut the ball back for Robin van Persie, who scored his 26th Premier League goal of the season.
That sparked further dominance from United and just after the hour mark veteran substitute Ryan Giggs played the ball across for Hernandez, who rolled it into the net from close range.
The Baggies were not done, though, and Chelsea loanee Lukaku claimed his second of the afternoon and his side's third when he rounded off a passing move with a simple finish, before Youssuf Mulumbu turned in a cross from Billy Jones with nine minutes left to bring them to within a goal of their visitors.
Remarkably, there was still time for West Brom to score their fifth goal when Lukaku completed a second-half hat-trick, as he bundled the ball over the line following a goalmouth scramble with four minutes of the match left to play.