Black Cats boss Roy Keane said Chopra's goal was a reward for his side's tireless efforts at a time when many of their rivals may have settled for starting their season without defeat.
Keane said: "We had plenty of late goals last season and I keep telling people it is not down to luck. We have the desire to keep going when other clubs might settle for a draw.
"It might cost us in other games but we had that desire to keep going. I am delighted for the players and I think we deserved the victory."
Former Newcastle man Chopra hit the net twice in a Cardiff shirt when the Welshmen visited the Stadium of Light last season and Keane said he had no qualms about bringing him back to the north-east.
Keane added: "Whether he's from Newcastle or New Zealand it doesn't concern me as long I think he can add something to the squad.
"I'm sure he was disappointed not to start the match but like any decent player he reacted in the right way. He didn't sulk. I looked at him on the bench and thought, he's keen to get on here."