The New York Knicks insist they remain confident, but their tone has shifted in the last few days.

When they held a 3-0 series lead, the Knicks seemed to dismiss the Celtics as little more than a speed bump en route to the second round, which the franchise hasn’t reached since 2000. But with the Knicks suddenly clinging to a 3-2 lead entering tonight’s Game 6 at TD Garden, they are no longer discussing the benefits of a quick end to the series.

“It’s not going to be easy by any means going to Boston and getting a win there,” Knicks coach Mike Woodson said. “But we still control our own destiny. We’ve got to see what we’re made of now.”

The Knicks’ overconfidence was illustrated by Kenyon Martin’s plan to have his teammates dress in black for Wednesday’s Game 5, sending a message that it would serve as the funeral for the C’s season. The stunt backfired, as the C’s won, 92-86, and it left Woodson irritated.

“That’s not important,” the coach said. “What you wear doesn’t have anything to do with how you play on the basketball floor.”

J.R. Smith ignited the Celtics’ fire by elbowing Jason Terry in Game 3 and further ratcheted up the bad blood with trash talk before Game 5. Smith didn’t speak to reporters yesterday, but he did spend extra time working on his jump shot after practice.

Smith averaged 16.3 points on 43.5 percent shooting before he was suspended for Game 4 for elbowing Terry. Smith missed his first 10 shots in Game 5 and finished 3-for-14 from the field.