Manchester United suffered a humiliating 4-0 defeat to a rampant Crystal Palace as the pressure piled on Erik ten Hag.

United were swatted aside with ease at Selhurst Park on Monday, with Michael Olise scoring twice in a superb performance from the Eagles, whose fantastic form under Oliver Glasner continued.

Olise opened the scoring early on before Jean-Philippe Mateta doubled Palace's lead before half-time – Tyrick Mitchell getting in on the act just prior to the hour.

Casemiro's calamitous error resulted in Olise hammering in a sublime long-range strike to compound United’s misery, and the eighth-placed Red Devils, who face Premier League leaders Arsenal on Sunday, are in real danger of missing out on the European places.

United's ramshackle defence was left exposed just 12 minutes in – Olise able to skip easily beyond Casemiro's shocking attempt at a challenge, drive into the box and, under little pressure, send a finish into the bottom-right corner.

Olise, who has been linked with a move to United, might have doubled his tally soon after, but Mateta could not get out of the way of his team-mate's goal-bound strike.

United seemed to have made their luck count when a goalmouth scramble resulted in the ball nestling into the back of Dean Henderson's net, but it was disallowed for Rasmus Hojlund's challenge on the Palace goalkeeper.

Olise squandered a brilliant chance to make it 2-0 when he elected to try and round Andre Onana at the other end, but the Eagles soon had their second when Mateta brilliantly slammed home from a tight angle after comfortably evading Jonny Evans.

Casemiro saw a goal ruled out for offside in the 53rd minute, but United's resolve was soon broken again as Palace swiftly reasserted their dominance.

Following two fine Onana saves, Mitchell tucked in from close range after United failed to clear their lines from a set-piece.

It was 4-0 in the 66th minute – Casemiro again at fault as he capitulated under pressure from Daniel Munoz. He teed up Olise, who curled a powerful effort down the centre of Onana’s goal to cap a famous win for Palace, who hit the woodwork late on through Odsonne Edouard. 

Palace's perfect night

While the attention will rightly be on just how bad United were, plaudits have to go to Palace. They have now won four of their last five league matches, scoring 13 goals in that run, and it has included victories over Liverpool, Newcastle United and now Man United.

Palace may be destined for a mid-table finish this term, but there is a real sense of excitement around Selhurst Park ahead of next season, with Glasner's feet now firmly under the table.

The Eagles are now unbeaten in four straight home league matches against United, who they have completed the double over for the first time.

While Olise starred, Mateta's thumping second was a real highlight, too. He has scored in each of Glasner's first six home Premier League games, becoming the first player to do so in the competition since Alan Shearer for Kevin Keegan in 1996-97 (first nine).

Problems pile up for Ten Hag as United's season reaches a new low

Harry Maguire and Bruno Fernandes joined United’s lengthy injury list in the build-up to this match, but even with those absences, United's fragility exposed deeper-rooted issues than just injuries.

Their defending was truly terrible in the first half, with Olise offered the freedom of Selhurst Park for his opener, as Casemiro and Evans struggled to cope – Kobbie Mainoo and Christian Eriksen offering little protection ahead of them.

United have now shipped 81 goals in 48 games in all competitions this season, their most in a single campaign since 1976-77 (also 81).

With Arsenal, fellow European hopefuls Newcastle and then Brighton still to play, those defensive frailties are a scary proposition for Ten Hag, who cut a glum figure on the touchline, and his team’s hopes of qualifying European football through their league placing is now out of their hands, given Chelsea are now above them.

The players were applauded by the travelling support after the whistle, but there will need to be a huge reaction against Arsenal.