Real Madrid knew that a win would take them top, but they suffered a blow just 28 seconds into proceedings when Fabio Silva ran off Lucas Vazquez’s shoulder to turn home Sandro Ramirez’s searching cross.
There was further disbelief at Estadio Santiago Bernabeu, as Brahim Diaz missed a glorious chance before Kylian Mbappe’s deflected attempt was tipped behind via the post by Jasper Cillessen.
Having assisted the opener, Sandro offered Real Madrid a route back into the game as he dangled a leg to bring down Rodrygo for a penalty that Mbappe coolly converted by sending Cillessen the wrong way.
With the hosts taking complete control of possession and applying pressure, Brahim saw a deflected attempt saved before Cillessen did brilliantly to palm away threatening attempts from Mbappe and Rodrygo.
The Dutchman impressively stopped Mbappe again in the 33rd minute but he was left helpless as Vazquez latched onto the loose ball and squared it for Brahim to score.
Mbappe then got another goal of his own just three minutes later by applying a clinical first-time finish to Rodrygo’s bouncing pass.
Mbappe had the ball in the net again but was denied a first-half hat-trick by an offside call, and he came agonisingly close moments later.
Naturally, all eyes were back on the Frenchman after the restart, and he was involved in the build-up as Fran Garcia cut the ball back for Rodrygo to place his shot in the bottom corner.
Their blistering start was now a hollow memory, and things got even worse for Las Palmas in the 64th minute, as half-time substitute Benito Ramirez completely missed the ball, caught Vazquez high with his studs and was sent off.
For a few moments, Jude Bellingham thought he had added his name to the scoresheet 10 minutes later, but his goal was ruled out due to Antonio Rudiger being offside before challenging for Rodrygo’s free-kick delivery.
Real’s first 90-minute win in three competitive matches had long been assured though, and they even had time to put the ball into the net for a sixth time, though Federico Valverde’s 88th-minute beauty was denied by yet another offside call.
After a night that also saw David Alaba come on to rapturous applause after 399 days out injured, Los Blancos once more sit above city rivals Atletico Madrid at the LaLiga summit.
As for Las Palmas, they have now suffered back-to-back defeats for the first time under Diego Martínez, and remain just three points above the relegation zone.
Flashscore Man of the Match: Kylian Mbappe (Real Madrid)