BOSTON

Isaiah Thomas has started a new trend that’s growing with each fantastic fourth quarter.

Thomas scored 19 of his 44 points in the final quarter to lift the Boston Celtics over the Toronto Raptors 109-104 on Wednesday night in a showdown for first place in the Atlantic Division.

When Thomas hits a shot in the fourth now, his teammates and many in the stands look down at their wrists, simulating looking at a watch to signal that it’s Thomas’ time.

“I just did it one game and it kept going,” he said. “I’ve got teammates, the fans, signs, everybody in social media is saying: ‘You know what time it is.’”

In his last game, Thomas had 24 in the fourth in a victory over Detroit. He’s had four games with 20 or more in the fourth. No other player in the league entered Wednesday with more than one.

“You have to trap him and get the ball out of his hands,” Toronto guard Kyle Lowry said. “He got three wide-open looks in the fourth. That can’t happen.”

It was the fifth straight win for Boston, which moved 1 ? games ahead of the Raptors in the division and holds the Eastern Conference’s No. 2 seed.

Jae Crowder scored 14 points for the Celtics and Al Horford had 11. Thomas had 18 of Boston’s final 23 points.

“He’s playing at a really high level,” Boston coach Brad Stevens said of his 5- foot-9 point guard.

Lowry led Toronto with 32 points, former Celtic Jared Sullinger had 13 and Norman Powell added 12. The Raptors have lost seven of nine.

“He’s more patient than ever,” Sullinger said. “He runs through the offense slowly and finds a way to score.”

In a final quarter that rivaled playoff intensity, Celtics forward Jaylen Brown was fouled on a breakaway attempt and walked over and had words with Lowry before a few others player joined in and had to be separated by the officials. Boston’s Terry Rozier and the Raptors’ DeMarre Carroll were each given a technical foul.

Notes — Raptors guard DeMar DeRozan was out for the fifth time in six games with a right ankle injury. … Celtics guard Avery Bradley missed his eighth straight game with a right Achilles tendon injury. Stevens said he’s practiced the last two days, but the team wants “to make sure that when we get him back, he’s back on the court and limit the chance that it’ll happen again.” … Forward Kelly Olynyk was out with a strained left shoulder. … Thomas hit a 36-foot 3- pointer with 2.5 seconds left to cap off his 16-point first quarter.

Next — The Celtics host the Los Angeles Lakers Friday night.