"I think there was a bit of excitement there for the fans and at half time we were encouraging each other - that wasn't us in the first half," he says.
Although Jermain hit the headlines for scoring a brace, David insists it was a team effort.
"He was aided by a decent performance from the rest of the team; the whole side facilitated his two goals, definitely," he says.
And he was delighted that Ian Pearce grabbed the winner.
"He deserved it; defensively in the first half the two goals were dire from anyone's point of view," he admits.
"The fact that we had only won one in the 12 games prior to the Sunderland game made it important especially with them being right by us on points.
"It has given us the opportunity to creep up on the leaders and with West Brom drawing the gap is only eight points so it is a lot healthier for us."