Kristaps Porzingis’s late buckets, Derrick White’s big 3 lift Celtics to 5th straight win

TORONTO — Last season the Celtics surged toward the top the hard way. By early March, they had already played 11 overtime games, and they carried the lessons and the bruises from these competitive matchups with them.

The start of this year has been comparably breezy. Entering Friday’s game against the Raptors, each of Boston’s last seven wins had come by double digits, with the new pieces blending seamlessly with the old ones to form the NBA’s most formidable team.

The Celtics were hardly crisp in this 108-105 in-season tournament win over Toronto. Coach Joe Mazzulla called it one of the team’s lowest-quality performances of the season. But that is what made it so valuable, a slice of imperfection that they will lean on as they pursue something big.

“Just a great game where we were fortunate enough to come out with a win, but we were able to learn a lot and feel a lot of the things that we hadn’t felt yet as a team,” Mazzulla said.

Jayson Tatum’s early MVP push took a brief pause, as he went just 1 for 11 from the 3-point range and did not attempt a free-throw during his 17-point night. And with the game hanging in the balance over the final 3 minutes, 20 seconds, neither Tatum nor fellow All-NBA talent Jaylen Brown scored a point.

But this Celtics team continues to show that it has an unusual number of weapons who can step into prominent roles when needed. Down the stretch Friday, Kristaps Porzingis and Jrue Holiday punished the Raptors with pick-and-rolls, and then Derrick White broke a tie by drilling the game-winning 3-pointer with 26.8 seconds left.

“I think we just kept playing all the way through,” Brown said. “I think we kind of sucked tonight. We didn’t play our best, but we figured out how to win anyway.”

Brown had 23 points to lead Boston, which improved to 2-0 in tournament group play with two games remaining. But afterward he was primarily frustrated about the new, custom in-season tournament court that he said caused him to slip several times during the game, including when he fell and suffered a possible groin injury in the final seconds.

“I think as players we’re all here for the in-season tournament because it’s going to generate revenue, excitement, competition,” Brown said. “But we’ve got to make sure the floor is safe to play on. We can’t put our players out there and risk their health. Tonight I thought the floor was unacceptable. I think guys were slipping all over the place, not just me.”

Porzingis registered 14 points, 12 rebounds, 5 assists and 3 blocks. With the Raptors switching on every screen down the stretch, Holiday twice found Porzingis for baskets inside in the final 90 seconds.

The Celtics won despite making just 34.8 percent of their 3-pointers (16 for 46). Last year, their success beyond the arc often served as a barometer for wins and losses. Mazzulla stressed throughout the preseason that the team must find a way to keep chilly shooting nights from defining them, and the early returns have been encouraging.

Last year the Celtics were just 15-19 when shooting below 35 percent from beyond the arc, and this year they are 4-2. They are making up the gap by crashing for offensive rebounds aggressively, closing quarters strongly, and seeking out free throw chances whenever they can.

“We had to learn a lot of stuff in that [win],” Mazzulla said. “And we haven’t had that this year. So it was good to have to really go through that.”

The Celtics led by 16 points at halftime and appeared headed toward another easy win.

But the Raptors started the third quarter with a powerful 3-point surge, draining four over the first 100 seconds to ensure that this game would not turn into an avalanche. Pascal Siakam — whose hot start was cooled when he sat the final 16 minutes of the first half after picking up his third foul — continued Toronto’s third-quarter run inside the arc, where his size and spin move gave Holiday some problems.

The Celtics called timeout after Siakam’s layup pulled the Raptors within 76-75, and on the next possession they sent two defenders his way and he found Jakob Poeltl for a layup that gave them their first lead since the opening quarter.

With the score tied at 97, both teams traded baskets over the next four minutes, with very little coming easily on either side. Tatum missed a pair of open 3-pointers that would have put Boston in control

But after Porzingis tied the score at 103 with an 8-footer with 1:01 left, former Celtic Dennis Schroder missed a runner before Holiday found White for a 3-pointer from the left corner, giving Boston a 106-103 lead with 27.1 seconds left.

Scottie Barnes got an open look from the right corner with 11 seconds to play but it skidded off the rim, and Boston held on for the win.

“We were just able to learn a lot of things and simulate a lot of things that we hadn’t been able to simulate yet,” Mazzulla said. “So we were lucky to win but if we don’t learn the things that we learned it’s not going to help us.”