Twenty-two minutes in at Leeds United a 5-1 win looked highly likely but how on earth did Crystal Palace get it?

Leeds United had picked up where they left off against Nottingham Forest, dominant and confident, even Brenden Aaronson exuding the self-belief he seemed to mislay somewhere en route to Qatar in November.

They were 1-0 up, Patrick Bamford having converted one of their 11 shots by that stage, and Crystal Palace had not mustered one. It felt like the opening 22 minutes had only been played in one half.

Leeds were going five points clear of the Premier League relegation zone with eight games left, pushing the Eagles closer to it in the process.

So how in God's name was it Palace who won 5-1?

"I cannot explain it," said Leeds coach Javi Gracia. Join the club, Javi.

Palace felt their way into the half via corners, Jeffrey Schlupp hitting a post before his side had good scoring chances from the other two, then equalised from a free-kick as it tipped into stoppage time.

And Leeds just stopped playing.

A fairly routine Marc Guehi goal in not especially unusual circumstances had knifed them through the heart when it should have been nothing more than a flesh wound.

Not only did Leeds stop attacking, they ceased defending, giving the taker of that decisive free-kick, Michael Olise, embarrassing amounts of space to make three goals – two in the first 10 minutes as Palace added four in all. All came in open play and far, far too easily.

Leeds remain two points above the relegation zone with their rivals playing before they host Liverpool. The ability they had shown to beat teams around them had deserted – temporarily, they must hope but the door has been opened to doubts just as they looked like locking it.

The incredible turnaround felt as much about the Whites as Palace.

"All Leeds are we" sang the home fans during the pre-match applause to Christopher Loftus and Kevin Speight and for 22 minutes, the game was all Leeds too.

In the end it would be another favourite Elland Road ditty – for away fans – which told the story. Leeds were inexplicably falling apart.

Bamford's 21st-minute header from an Aaronson corner – his 50th goal for the club – was the least his team deserved.

Luis Sinisterra dragged a shot wide, headed firmly at Sam Johnstone, then not got enough on a diving header. Johnstone had made the first of three brilliant saves when Aaronson got a clever flicked finish to Junior Firpo cross.

Bamford's shot wide from distance was one of confidence even if it missed the target but he soon made up for it.

His goal woke Palace up, as shown by Schlupp's header two minutes later from their first corner, Firpo having to clear Guehi's goalbound effort from the second and the defender heading wide from the third, but it did not change the overall flow of the game.

Johnstone still had to perform heroics to keep out from Jack Harrison's low curling free-kick and Pascal Struijk's header.

Guehi's goal, latching onto the ball as it came off Schlupp's back, was just a slap on the wrist for being so wasteful and standing looking at the linesman to bail them out without playing the man offside first. The second part of that equation would repeat itself.

At half-time Leeds made 11 substitutions, bringing on a team of lookalikes lacking ability or the nous to close players down. There can be no other explanation.

In the 53rd minute Ayling's twin put a baffling amount of air on a pass, practically begging Joel Ward to win the header against too little resistance from Harrison's doppelganger. Palace powered down the right and when the ball came across Ayling's boots were in concrete as Jordan Ayew ran in front to head in.

Twice Olise had far too much space to pick a killer pass. Eberechi Eze ran onto the first to make it 3-1.

The second came after a spell of pressure saw Harrison lay a deep cross back to no one, Tyrick Mitchell dispossess Bamford after a couple of stabbed passes played him in, and Ayling miskick a volley. Palace broke with Oilse in so much space he must have wondered if he had not heard the whistle but he carried on and picked out Ayew.

With 20 minutes to go, Leeds fans headed for the exits.

"We want five!" chanted away fans who would have been grateful for one not long earlier.

Illan Meslier's outstretched glove just stopped Ayew taking the ball around him but two minutes later Leeds stood still assuming the striker was offside from Will Hughes's deflected shot. Rasmus Kristensen was playing two attackers on.

Olise should have scored a sixth, twisting into a scoring position only to blast over. By then the surprise was that Palace only won 5-1.

Leeds United: Meslier; Ayling, Koch, Struijk, Firpo (Kristensen 60); McKennie, Roca; Harrison, Aaronson (Gnonto 60), Sinisterra (Rodrigo 60); Bamford (Rutter 79). Unused substitutes: Forshaw, Cooper, Summerville, Robles, Greenwood.

Crystal Palace: Johnstone; Ward (Clyne 86), Andersen, Guehi, Mitchell; Eze, Doucoure (Milivojevic 80), Schlupp (McArthur 80); Olise, Edouard (Hughes 74), Ayew (Mateta 80). Unused substitutes: Tomkins, Lokonga, Whitworth, Riedewald.

Referee: S Hooper (Swindon).