Jaylen Brown had the ball knocked away while facing a double-team, and it caromed directly toward White in the right corner. Raptors guard Alijah Martin sprawled for the ball but missed it, and when White gathered it, his back was facing the basket. He quickly spun, aware that Martin could find his way back into the play soon, and fired up a 3-pointer just an instant after recalibrating on the rim.

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The ball splashed through the net, igniting the 14-2 run that helped the Celtics hang on for a 121-113 win, their fifth in a row.

“[Martin] actually got back into the play, which kind of surprised me,” White said. “But I was still able to knock it down. So, it’s kind of a weird one. Maybe those trick shots are working out for me.”

The Celtics’ winning streak seemed to be gaining steam as it progressed. Boston never trailed in its last two wins over the Wizards and Lakers, and most of this matchup unfolded similarly.

The Celtics stormed ahead early behind a 77-point first half and stretched their advantage to 87-64 early in the third. But this time they would have to pass a stress test as Toronto roared back to take its first lead of the day and give the Celtics their first deficit since Tuesday.

But in the long term, this teachable moment will likely have more value than another blowout.

“We didn’t meet the physicality that the segment of the game required,” coach Joe Mazzulla said. “But then we snapped out of it and got right back into it. That’s a credit to the guys. You’re not going to play a perfect game all the time, and you always talk about, ‘How quickly can you get back to your best?’”

Jaylen Brown had 30 points, 8 rebounds, and 5 assists to lead the Celtics (15-9), and White added 27 points. The Celtics shot 47.8 percent from the field and made 20 of 47 3-pointers. Brandon Ingram had 30 points to pace Toronto (15-10).

NBA standings can fluctuate wildly at this point in the season. Nevertheless, it feels notable that Boston, which started 0-3 and ignited early questions about whether this would be a gap year with Jayson Tatum out, pushed into third place in the Eastern Conference with this victory, its 10th in 12 games.

“I didn’t expect us to see this amount of growth this soon,” said Brown, who registered his 13th 30-point game of the season. “I knew it would happen as we continued to go about the journey, but to see it blossom 24, 25 games in is a great sign for us.”

Brandon Ingram (left) scored 30 points for the Raptors, but Derrick White countered with 27 and started the Celtics’ winning rally.Chris Young/Associated Press

The Celtics took an 87-64 lead on a Payton Pritchard 3-pointer with 8:30 left in the third quarter. But the Raptors clawed back by raising their level of physicality and putting pressure on the Celtics in transition.

Ingram ignited the comeback with a fadeaway jumper and a layup. The Raptors made all three 3-point attempts in the quarter and blitzed the Celtics with a 23-4 run that put a jolt into a crowd that had begun to lose interest. Toronto held a 12-0 edge in fast-break points in the period and pulled within 97-91 by the start of the fourth.

A fast-break layup by Jamal Shead with 10:39 left gave Toronto a 98-97 lead, its first. After the Raptors stretched it to 3, though, White’s big shot tied the score at 102.

Payton Pritchard added a 3-pointer from a similar spot on the next possession, and after a 21-footer by Brown, White and Pritchard added two more 3-pointers to stretch the surge to 14-2 and give the Celtics a 113-104 lead that held up.

“We just assumed it was going to be our turn to make a run,” said center Neemias Queta, who had 11 points and 11 rebounds. “We started playing a little bit harder defensively going for loose balls and I think we shifted the momentum of the game then.”

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him @adamhimmelsbach.