Sir Alex Ferguson was frustrated at Manchester United's inability to kill off Fulham at Craven Cottage and felt Ryan Giggs should have taken the critical penalty.
United were held to a 2-2 draw but looked poised to join Chelsea at the top of the Barclays Premier League when Nani stepped up for an 86th-minute spot-kick, but his attempt was saved by David Stockdale and Brede Hangeland nodded home the equaliser with a minute to go.
Ferguson admitted United, who were missing Wayne Rooney because of a virus, had slipped up and he told MUTV: "When you get the opportunity to seal the game with that penalty you should be taking it. I thought Ryan should have taken the penalty. It was a missed opportunity and it galvanised them, got the crowd up and they scored the equaliser in the end."
He added: "When we got that second goal I thought 'we've escaped here'. But to miss a penalty kick to make it 3-1, you're throwing two points away there I'm afraid.
"You don't want to be dropping silly points and we dropped silly points. We can't escape that.
"In the last game we played against Tottenham at home Ryan scored two penalty kicks and Nani was on the pitch the same day."
Paul Scholes capped an ominous start for United when he powered home a low 25-yard drive in the 11th minute with Fabio Capello watching from the stands.
Reports suggest Capello may appeal to Scholes for a second time to end his international retirement and the midfielder's influential first half only served to highlight his potential value to England.
Ferguson was delighted by the 35-year-old's display which was capped by his 150th goal for United.
"We've seen that type of goal before from Paul - he's done that so many times," he said. "Once again it was an outstanding performance from him. It's just disappointing we didn't ram home the advantage."