Both sides looked impressive in the opening stages but the controversial dismissal of Matheus Pereira turned the game in Palace’s favour after the break.
Palace were quick to turn on the style in the West Midlands as talisman Wilf Zaha carved out the opener inside the first five minutes.
His pace took him away from three Baggies defenders and his fizzed cross into the box was diverted home by West Brom defender Darnell Furlong.
Furlong looked to be on a one-man mission to make up from his error after that as he smacked a header off the bar and played a key role in the Baggies equaliser.
Semi Ajayi’s pass sent him clear behind the Palace defence and Chelsea loanee Conor Gallagher arrived on cue to tuck away his cross.
That breathed some life back into Slaven Bilic’s team but the Croatian was left incensed as Pereira was sent off on 34 minutes.
The Brazilian tangled with Patrick van Aanholt but VAR ruled a kick out by him and Paul Tierney opted to flash a straight red.
That completely changed the complexion of the match after the restart as Zaha curled home a beauty on 55 minutes.
Palace simply powered on from there as Christian Benteke nodded home from van Aanholt’s cross and Zaha tucked home from Eberechi Eze’s pass.
And with Bilic’s hosts on the ropes in the final minutes, Benteke grabbed his second of the day, as he powered home Nathaniel Clyne’s cross.
Full Time at The Hawthorns it’s West Brom 1 Crystal Palace 5