BOSTON -- As the fourth quarter of Friday night's game here between the Celtics and Toronto Raptors began, Kemba Walker was desperate to finally get going after an abysmal first seven quarters in a Celtics uniform.

But then, just as he did so many times over the past eight seasons in Charlotte, North Carolina, Walker came through when his team needed it most, scoring 11 of his 22 points in the fourth quarter to lead Boston to a 112-106 victory in the Celtics' home opener in front of a sellout crowd at TD Garden.

"I was so happy," Walker said afterward. "Like, 'About time.' It was a struggle, even from last game [Wednesday night in Philadelphia] to tonight.

"I wanted to kind of be myself, and these guys just allowed me to."

To say Walker had struggled during the first seven quarters of the season was an understatement. After going 4-for-18 overall, and 1-for-6 from 3-point range, in Wednesday's loss to the 76ers, Walker was just 4-for-13 overall and 1-for-5 from 3-point range entering the fourth quarter Friday night.

Once he checked into the game with 9:18 remaining, however, it quickly became clear things were going to be different.

Walker immediately got into the lane and made a pull-up jumper, and he followed that up with a 3-pointer on the following possession. Suddenly, Walker was hot, and he began to look like himself again. He made two nifty drives into the paint for scores sandwiched around a Robert Williams alley-oop layup, and then another attack at the rim resulted in him getting a pair of free throws.

By the time he was done, Walker had scored 11 of Boston's 13 points over a stretch of 2 minutes, 37 seconds to keep the Celtics in the game, as the Raptors got hot at the same time. Walker then later hit Grant Williams with a pass for a layup to give Boston a 101-100 lead and found Jayson Tatum on the wing for a 3-pointer to make it 104-100 Celtics with 4:33 remaining.

Boston would never trail again.

"I can't say enough about the people around me," Walker said. "The coaching staff, most importantly my teammates just really keeping me confident -- they kept talking to me throughout the game. They knew I wanted to play well and I wanted to make shots, but I was struggling. But I can't say enough about it. They kept me confident. I really just appreciate those guys for keeping me level-headed, keeping me confident and just allowing me to be myself."

Walker is more than familiar with fourth-quarter success. Last season, according to ESPN Stats & Information research, Walker was third in the NBA in fourth-quarter scoring with 8.0 points per game, trailing only LeBron James (8.6) and James Harden (8.3).

And Boston certainly needed that kind of boost after that ugly loss Wednesday in Philadelphia looked like it could easily be followed by another one here after Toronto -- which got 33 points and eight rebounds from Pascal Siakam and 29 points, four rebounds and seven assists from Kyle Lowry -- led by six points after three quarters.

But Boston outscored Toronto 36-24 in the fourth to come from behind and get the win, with Walker not only leading the way offensively late but also drawing multiple charges in the game -- including one on OG Anunoby with 1:31 remaining and the Raptors trailing by four to help seal the victory.

"He's always done that," Celtics coach Brad Stevens said. "When [Team USA] beat Turkey in that overtime game, he took two charges in overtime that were as big as any of the shots he hit. He's just always been a guy that's willing to put his body on the line. You could see that he was pressing early and he missed a bunch of shots that I think he'll normally hit.

"Then he got his -- when he starts getting going downhill like that, he makes the little pull-up, then pulled up for the 3, then he got into the body of the big a couple times and he made those layups. He just looked like he had an extra gear and he probably wasn't thinking about it going in -- he was just going to be Kemba Walker."