Boss Ole Gunnar Solskjaer admitted Manchester United have no room for error in their top-four quest after conceding they blew it at Wolves.
Chris Smalling's own goal condemned 10-man United to a 2-1 defeat – their third in four games – as they missed the chance to climb back into the Champions League spots.
Scott McTominay's first United goal put the visitors ahead but Fred's mistake allowed Diogo Jota to level in the first half and Ashley Young was sent off mid-way through the second half for two bookings in five minutes.
United remain fifth in the Premier League, behind Tottenham on goal difference, with six games left and face Barcelona in their Champions League quarter-final first leg next week.
Solskjaer said: "I said we needed 15 points from the last seven games (to make the top four), we now need 15 in the last six, so we don't have room for many more losses.
"We are a very good team, so it'll be difficult for anyone playing against us. Our performance deserved the win.
"We created our own downfall. It was a very good performance until they scored their second goal.
"But for their keeper we should have won. We created enough chances to win the game so I don't think there's any 'resetting' (after his fast start as United manager)."
Defeat came just over two weeks after United lost 2-1 in the FA Cup quarter-final at Molineux.
Ander Herrera, who has been linked with a move away from the club, was injured while Marcus Rashford was sidelined with an ankle problem.
United, though, should have been 3-0 up inside 16 minutes as Romelu Lukaku and Jesse Lingard missed glorious chances either side of McTominay scoring his first goal for the club.
Jota levelled after 25 minutes after Joao Moutinho robbed Fred following David De Gea's short pass and it got worse for United when Young saw red after 57 minutes for his second foul on Jota – referee Mike Dean's 100th Premier League dismissal.
Solskjaer added: "When you're on a yellow you're always in danger if you go down, it's a yellow card. It was probably a bad decision (from Young)."
Smalling put into his own net from close range with 13 minutes left to win it for Wolves, who sit seventh in the league ahead of Sunday's FA Cup semi-final against Watford.
Boss Nuno Espirito Santo picked his strongest side despite their Wembley trip and insisted he did not consider resting players.
He said: "No, there's no such thing. There was the game, there was a game plan, we take the decisions and the options and we prepare for the next one.
"The preparation for the next game starts tomorrow.
"Two very good results against such a good team requires a lot and the boys worked very well.
"I'm pleased with the performance, that's what is important. To do it twice makes the effort worthwhile. It's not easy to play against Man United."
