Leonardo Ulloa scored twice, either side of David Lopez's free-kick, to deny the Eagles the chance to go second in the npower Championship.
Poyet said: "It's my best day here as manager. The day we went up from League One was special. But this is the best day by far."
He added: "I become a fan of the club I am working at or playing for, it's how I am. And at this football club you know one thing - you need to beat Palace.
"This was a day to stop time and stay here forever. I would like it to be the last game of the season, or a last at a club, or the last of your career."
Palace boss Ian Holloway was left to reflect on a pretty miserable afternoon.
"We didn't take our opportunities in the first half, it was pretty tight, and then all of a sudden we are two down at half-time," he said.
"We changed things at half-time, but then they scored one of the worst goals that this lot have let in.
"It's very disappointing for us, we could have gone second.
"And the roof here is too short. My coat's ruined. I'm soaking wet. I've had better days."