"Football is crazy" was manager Louis van Gaal's frank assessment after Manchester United rode their luck at Crystal Palace to bring their losing streak to a timely end.

Defeats to Chelsea, Everton and West Brom saw the Red Devils arrive in south London looking to avoid a run of four straight losses in the same season for the first time since 1961. There were moments when it looked like that may well happen, especially after Jason Puncheon cancelled out Juan Mata's dubious penalty with a second-half free-kick.

However, United saw out the storm – thanks in no small part to goalkeeper David de Gea's fine display – and snatched a 2-1 victory, with Marouane Fellaini capitalizing on a collision between Julian Speroni and Damien Delaney to head home the winner.

The triumph may have been unconvincing, but it opened up a seven-point lead over fifth-placed Liverpool, whose slim Champions League hopes will be ended if they lose at Chelsea on Sunday.

"Football is crazy," Van Gaal said, following United's fortuitous win.

"When you see how we have played against Chelsea, Everton and West Bromwich Albion and you compare it with today, in that row of matches this was not our best match. But you win and that is also the beauty of football

"What I have seen today is a fighting spirit of my team and that I have said to my players, 'When you fight like you have fought today, we are difficult to beat'.

"I am very happy with this result. It brings us a big step closer to our goal and now I we shall sit (on Sunday) with a fantastic glass of wine to see the match Chelsea against Liverpool."

Van Gaal joked he may switch to champagne should the result at Stamford Bridge go their way – "When I don't drink too much red wine, then maybe" – and United's return to the Champions League be confirmed.

De Gea deserves a lot of credit if they return to the top table of European football, and at Selhurst Park the Spaniard underlined his position as one of the best goalkeepers around.

"He made a great save at the most important moment," Van Gaal said, referring to an exceptional stop to deny Glenn Murray.

"At that time Crystal Palace could score the second goal and then it shall be very difficult for us to come again in the match."

Palace did well to get themselves into that position after falling behind to Mata's early penalty – a decision which frustrated Palace boss Alan Pardew.

Pardew did not want to come across as a "moaning minnie", but thought the handball was harsh on Scott Dann, while he felt Radamel Falcao pushed Delaney in the build-up to Fellaini's winner.

"Well, I am a bit aggrieved about the penalty, obviously," Pardew said. "I think from the referee's angle that's a real tough call on us.

"Scotty Dann does gesture with his body, but he is away from the referee and the referee's angle can't be sure that's hit his arm.

"I asked him that after and he said he just went with his gut feeling that it was a penalty, but after the players' reaction and seeing it on VT I think that was a really tough call.

"First half, Man United played well, they dominated possession, their rotation in midfield caused us a problem and we couldn't really get to grips with them until the second half when we changed our shape.

"That helped us. We started to boss the game and we started to have a lot more control of possession, got the equalizer and had a great moment to take the lead.

"Only a fabulous save from the goalie – who I thought was outstanding all game, his kicking and his distribution was really on the money – probably prevented us from winning that game.

"Then, lo and behold, a little bit of a collision and a couple of little pushes, whatever, for the second goal has cost us what would have been a great point for us, even if we didn't win the game."