Vinny Del Negro joked Sunday that something in the Canadian air caused his Clippers to play their worst game of the season in Friday's blowout loss to the Toronto Raptors.

Whatever it was, the Clippers evidently brought it with them back to their home country – at least for the first half of their Sunday matinee with the Boston Celtics – before finally expelling it late in their tight loss at TD Garden.

The Clippers were outscored by 19 in Sunday's first half before making a strong run to close the game. However, Paul Pierce's 3-pointer with two seconds left gave the Celtics the 106-104 victory.

"If we would've came in with the same effort and energy we had in the second half, I think it would have been a different outcome," said Clippers guard Jamal Crawford, who tied for a game-high with 23 points off the bench.

The Clippers went on a 21-8 run in the fourth quarter and got to within 103-101 before Pierce's 3-pointer.

Crawford noted that the Celtics' aggression mirrored what the Clippers look like on their best days. Boston set Sunday's tempo and forced L.A. to play uncomfortably early.

"That's what we do to teams when we're successful," he said.

Eric Bledsoe, starting for an injured Chris Paul, also had a career-high-tying 23 points for the Clippers – and 10 assists. Blake Griffin added a 20-point, 11-rebound double-double.

The Clippers blamed their collective defense for the loss, with reserve forward Matt Barnes pinpointing it directly on a lack of effort.

"We just haven't played well defensively, and I think that's the key to our success," Griffin said. "We have to be on our rotations defensively and really bring the energy to withstand poor shooting."

Griffin and the Clippers actually shot quite well for most of Sunday's game – 59 percent excluding the fateful second quarter, in which they were outscored 26-10 for their worst scoring period of the season.

"The second quarter was the difference in the game tonight," Del Negro said.