Manchester United manager Sir Alex Ferguson believes Tottenham Hotspur goalkeeper Heurelho Gomes must shoulder the blame for gifting the Red Devils their clinching goal in Saturday's 2-0 win at Old Trafford.
The Brazilian shot-stopper bowled the ball out of his hands anticipating a free-kick after Nani had handled in the penalty area.
But referee Mark Clattenburg waved play on after Nani's indiscretion and the Portuguese winger rolled the ball into the empty net.
The whistler allowed the goal to stand, much to Spurs' disgust but Ferguson insists the keeper should have known better.
"It was bizarre," he said."No-one knew at the time what was wrong. One minute the goalkeeper had the ball in his hands and the next it's in his net.
"Nani looked back and looked at the referee and the referee said play on, so what can he do but put the ball in the net.
"You can look at the referee and look at the linesmen and blame them, but the goalkeeper should know better. He's an experienced goalkeeper. I thought he made a mess of it.
"The referee played on because the goalkeeper took possession of the ball. He then went to take a free-kick thinking it was a foul. He made an error."