A stoppage time goal from Robin Van Persie gave Manchester United an FA Cup lifeline after a highly entertaining 2-2 draw at Upton Park.
Joe Cole nearly had a perfect second debut for the Hammers following his recent free transfer from Liverpool after providing assists for both West Ham goals, but the Dutch international striker came on from United's bench to devastate the home players and fans.
Tom Cleverly put the Red Devils in front after 23 minutes with a great strike, after some really poor defending from the Hammers left the midfielder all on his own upfront.
But the home side were back in the game soon after when James Collins burst forward to head in a great curling cross from man-of-the-match Joe Cole.
The same partnership was in action again shortly after the break as another cross from Cole was well converted by Collins, who rose above the entire United defence to head the Hammers in a fully deserved lead.
The home side managed to hold on for the majority of the second half, staying steadfast against chances from Ryan Giggs and Antonio Valencia, and somehow managed to miss a crucial chance to win the tie, but Carlton Cole failed to turn the ball past David De Gea from close range.
Their defence finally succumbed to the pressure from United with three stoppage time minutes to go, as substitute Van Persie scored with a trademark low strike across goal after a crafty 50-yard pass from Giggs.
West Ham will feel they deserve the win but will now have to travel to Old Trafford to settle the tie.