"We didn't want the break because we were on such a good roll," said Chopra.
The front man scored the opening goal before his rebounded shot was finished off by Riccy Scimeca.
"No doubts came in when they equalised, we never give up and find a bit extra to win games," said Chopra.
"We knew it would be tough, but we had a great start and that made it hard for Palace to get at us.
Chopra praised the fans who outsung the home crowd.
"Some great support from the travelling fans spurred us on, and it was fantastic to see Riccy pop up to turn in the winner.
"People talk about him as a defensive midfielder, but he's come up with a lot of vital goals this season."