But it was Watford who secured a last-four date at Wembley when Gray, who had replaced Will Hughes, volleyed a 79th-minute victor to send their fans home dreaming of a second FA Cup final appearance after they lost the 1984 showpiece.
Watford's Andre Gray celebrates at the end of the match against Crystal Palace at Vicarage Road in Watford, March 16, 2019.
LONDON, March 16 ― Andre Gray came off the bench to fire Watford into the FA Cup semi-finals with the late victor in their 2-1 victory over Crystal Palace today.
The Hornets had earlier led through Etienne Capoue's instinctive finish before Michy Batshuayi leveled for the Eagles, finishing coolly after dispossessing Adrian Mariappa.
But soon after replacing Will Hughes, Gray fired past Vincente Guaita to send his club into only their sixth FA Cup semi-final.
The former Burnley striker has now scored the victor as a substitute three times in recent weeks, having also netted Watford's decisive goal against Everton and Leicester.
He volleyed in a 79th minute victor to send their fans home dreaming of a second FA Cup final appearance, after the 1984 showpiece which they lost.
It was a mistake he repeated with fatal consequences as Watford took the lead in the 27th minute.
Watford threatened a second goal when Deulofeu unleashed a rising shot moments later, but this time Guaita was up to the task.
The visitors, already weakened by the absence of the influential Mamadou Sakho, were further undermined when fellow central defender Scott Dann joined the injured Wilfried Zaha in withdrawing, this time through illness.
The former Chelsea man then advanced before opening up his body and shooting past Gomes.
But Gracia responded by sending on Gray in the 77th minute and it proved an inspired move as he won it for Watford just two minutes after his introduction.
Roberto Pereyra was the catalyst with an incisive burst from midfield and the Argentine's perfectly-placed pass picked out Gray, who timed his run to poke a volley past Guaita from eight yards.
In stoppage time Aaron Wan-Bissaka had the chance to score the latest of undeserved equalising goals, but from just outside the area he shot narrowly wide.