The Ivory Coast international was once again in imperious form to move the Eagles six points above the relegation zone and within touching distance of safety.
The 25-year-old has endured a difficult week after being booked for diving during last weekend's 0-0 draw with Watford, but will make headlines now for the right reasons after a dazzling display.
In a first half that was played at breakneck speed, Zaha kept his cool to emphatically finish a flowing team move after 17 minutes.
He was denied a second by Ben Hamer soon after, but turned provider for James McArthur in the 38th minute as Roy Hodgson's side scored the second their dominance deserved.
Marc Albrighton took drastic action to prevent Zaha netting a third shortly after the restart, hauling him down when clean through on goal, resulting in a red card on a miserable afternoon for Claude Puel's side.
Leicester, who are without a win in four games, fell apart in the closing stages, allowing Ruben Loftus-Cheek and Patrick van Aanholt to add gloss to the scoreline, before a rare Christian Benteke goal completed the thrashing from the penalty spot.
FULL-TIME Crystal Palace 5-0 Leicester City— Premier League (@premierleague) April 28, 2018
Wilfried Zaha, James McArthur, Ruben Loftus-Cheek, Patrick van Aanholt and Christian Benteke show no mercy on 10-man Leicester#CRYLEI pic.twitter.com/1xLUrra5Nb
The hosts started with a verve that was sorely missing from last weekend's tepid draw at Watford, with Andros Townsend testing Hamer and James Tomkins seeing an effort deflected wide inside the opening five minutes.
Hamer then almost gifted Palace the lead, his skewed punch from a corner landing on the head of Tomkins just six yards out. The former West Ham defender's downwards header, however, was cleared off the line by an alert Kelechi Iheanacho.
At the other end, Leicester came agonisingly close to taking the lead against the run of play, but Joel Ward got back to clear Jamie Vardy's low drive off the line.
The importance of Ward's intervention was highlighted just moments later when Zaha scored his eighth Premier League goal of the campaign.
Loftus-Cheek started the move by playing in Yohan Cabaye, who in turn fed McArthur. The Scot then found Zaha with an impudent back-flick and the Ivorian showed supreme confidence to lash a fine strike into the roof of Hamer's net.
A rampant Zaha was denied a second soon after when Hamer got down well to tip his volley wide of his left-hand post.
Leicester's defenders could scarcely get near to the Ivorian and he found another pocket of space seven minutes before the interval to tee up McArthur for the Eagles' second.
The Scot picked up Zaha's pass inside the penalty area, swivelled and dragged a low shot past Hamer and into the bottom corner to double their advantage.
Any hopes that Leicester had of clawing their way back into the game were extinguished 11 minutes after the restart when Albrighton received his marching orders.
The midfielder – who had found himself as the last man – had his pocket picked by Zaha before unceremoniously hauling him down with only Hamer to beat.
Hodgson's side then made their numerical advantage count in the closing 10 minutes.
On-loan Chelsea midfielder Loftus-Cheek latched onto Mamadou Sakho's smart throughball to round Hamer and slot into an empty net, while Dutch defender Van Aanholt whipped in from the edge of the area after the ball had fallen kindly to him.
Benteke then got in on the act, slotting home from the spot after Harry Maguire had clumsily brought him down in the box.
Key Opta stats:
- Crystal Palace enjoyed their joint-biggest winning margin in a top-flight game, matching their 5-0 mauling of Manchester United in December 1972.
- Leicester shipped five goals without scoring themselves for the first time in the league since January 2004 (5-0 loss at Aston Villa in the top flight).
- Palace have won two top flight games in a season against the same opponent by a margin of at least three goals for the first time ever.
- Leicester have picked up five red cards in the Premier League this season, more than any other side.
- The Foxes are the first side this season to see a player sent off against the same Premier League opposition both home and away.
- Wilfried Zaha has scored four goals in his last four Premier League games, as many as in his previous 24.
- Only Chris Armstrong (23) has scored more Premier League goals for Crystal Palace than Zaha (21, level with Andrew Johnson).