Crystal Palace staged a remarkable second-half turnaround to give a significant boost to their Premier League survival hopes and leave stunned Leeds with plenty of work to do in their own bid to avoid relegation.
The Eagles scored four goals after the break with Jordan Ayew - in for the injured Wilfried Zaha - scoring two in an incredible demolition of the home side.
Such a victory looked hugely unlikely after Patrick Bamford's 50th goal for the club gave Leeds the reward their early dominance deserved.
But from then on it all went downhill as Marc Guehi flicked in an equaliser on the stroke of half-time before Palace scored two goals in two minutes soon after the break.
First, Ayew made it 2-1 with an excellent header before Eberechi Eze added a quick third, poking in from Michael Olise's pass.
Odsonne Edouard drove a fourth into the bottom corner following a quick counter - with the excellent Olise providing the assist again - and Ayew completed the rout late on when he lifted a shot over Illan Meslier, prompting many Leeds fans to leave.
The stunning win moves Crystal Palace up to 12th in the Premier League, six points clear of the relegation zone, while Leeds are 16th, just two points above the drop.
There were concerns that Leeds would pay the price for not making the most of their first-half dominance, but no-one could have foreseen what would unfold at Elland Road after the break.
For as sharp and hungry as they were in the first 45 minutes, Leeds were disjointed and lethargic after the break as the players and fans were left in disbelief as Palace tore them apart with clinical efficiency.
As good as Leeds are going forward, a question mark remains over their defence and they left huge gaps that the excellent Olise took great joy in exploiting as he claimed a hat-trick of assists.
Only Bournemouth have conceded more goals than Leeds' 54 this season and that is the area Javi Gracia will need to address quickly to ensure his side are playing Premier League football again next season.
