Blackburn pulled off the biggest surprise of the Premier League season so far by stunning Manchester United 3-2 at Old Trafford on Saturday to ruin Alex Ferguson's 70th birthday.
United had erased a 2-0 deficit through two second-half goals by Dimitar Berbatov, but Grant Hanley took advantage of a mistake by goalkeeper David de Gea to score the winner from a corner in the 80th minute.
The 20-year-old Hanley beat De Gea in the air to get his head on the ball and then headed it into the net with a second effort to secure a victory that eases the pressure on under-fire Blackburn manager Steve Kean.
It also prevented United from ending the year atop the standings, as it remained behind crosstown rival Manchester City on goal difference.
"We've lost two terrible goals in the game, and we can't do that in a game like this," said Ferguson, who earlier marked his birthday by pledging to stay in his job for at least another three years. "
Ayegbeni Yakubu had scored the first two for Blackburn, with a first-half penalty and a low shot past De Gea in the 51st, before Berbatov struck back with two quick finishes inside the area.
But United couldn't stage a second comeback, as the closest they could come was an injury-time shot from former Blackburn defender Phil Jones that was cleared off the goalline.
United fielded an unfamiliar lineup due to injuries and illness, with Wayne Rooney and Ryan Giggs both being left out of the squad, and went behind to Blackburn's first real attack after 15 minutes.
Goalkeeper Mark Bunn punted forward a long free kick in the direction of Yakubu, who was hauled down by Berbatov in the area.
Referee Mike Dean had no hesitation in pointing to the spot and Yakubu gave his team an unexpected lead with a confident penalty into the bottom left-hand corner of the goal.
United, with right back Rafael da Silva playing in central midfield, failed to put Bunn under real pressure in the first half, although the goalkeeper did well to keep out shots from Nani and Javier Hernandez.
Yakubu then doubled the Rovers' lead five minutes into the second half with an individual effort.
Collecting a throw-in halfway into United's half, the forward eased past Rafael and was helped by a fortunate bounce from Michael Carrick's attempted tackle before beating Jones and finishing powerfully into the far corner of the net.
United responded quickly, however, pulling back a goal on their next attack, as Rafael crossed for Berbatov to score with a close-range diving header.
United kept pressing, and Bunn saved well with his feet to deny Patrice Evra before Berbatov scored his second. Antonio Valencia picked out Berbatov, who slotted in a low finish from 10 yards.
United looked likely to add a third, but Bunn saved a curling shot from Nani, while Jones headed over and Valencia missed from a promising position.
"I thought at that point we were set to win it," Ferguson said.
But Blackburn made them pay when Hanley rose above de Gea to meet Pedersen's corner with an attempt on goal. With de Gea on the ground and his defense slow to react, Hanley was then allowed time to reach the loose ball and force it over the line with a follow-up header.