BOSTON -- It was a long five days between when Kemba Walker crashed to the floor in Denver on Friday and when he took the court with his Boston Celtics teammates Wednesday night at home against the Brooklyn Nets.

But on a night that was supposed to be all about Kyrie Irving, the man who replaced him here at point guard, Walker, played like he hadn't missed a minute, finishing with a season-high 39 points to lead the Celtics to a 121-110 victory over the Irving-less Nets in front of a raucous sellout crowd at TD Garden.

"I've been over it," Walker said after the game of the sprained neck he suffered against the Nuggets. "I mean, I could have played last game, honestly.

"But if I'm on the court, I'm on the court. That's really it. I wasn't out there thinking about anything. I wanted to win."

The Celtics were able to win, and they remain undefeated at home (7-0) this season, thanks in large part to Walker's heroics.

The Nets made 21 3-pointers -- including 19 after the first quarter -- and there were times when it appeared they could pull away from Boston. That was especially true in the second and third quarters, when they combined to go 15-of-28 from 3-point range.

Instead, Walker matched the Nets shot for shot, scoring 13 points in each of those quarters. That allowed the Celtics to stay in the game until Brooklyn began to cool as the second half wore on, and Boston's depth -- plus that home-court advantage -- could begin to work in its favor.

"Kemba kept us in it in the second quarter as they were going through their flurries of 3s," Celtics coach Brad Stevens said. "He kept hitting huge shots, and that allowed us to stay in the game.

"We've all seen many times when teams get hot, and it's hard to sustain over the course of the whole game. We knew how urgent we had to play in the second half, because of the way they were."

Given where things stood Friday night, when Walker was taken off the court in Denver on a stretcher after crashing into Semi Ojeleye's midsection, the Celtics were thrilled to have him back on the court so soon -- let alone playing the way he is.

"I would say so," Stevens said, when asked if both Walker's quick return and his play Wednesday were the best-case scenarios for Boston. "Sometimes it looks bad and it's not with head and neck injuries, and sometimes it looks not as bad and it can be really bad.

"We are all really happy that Kemba is OK and feel very fortunate. I know he does, too. For him to be playing and even feeling fresh five days later is good. He was unbelievable tonight."

While Walker was doing it all for the Celtics -- he was 13-of-24 from the field, 6-of-10 from 3-point range, 7-of-7 from the foul line and had six rebounds and four assists -- there was plenty of attention being paid to Irving, despite the fact he wasn't in the building.

The Nets announced last Friday that Irving, who has now missed seven straight games with a right shoulder impingement, wouldn't attend Brooklyn's three-game road trip.

At various points, the crowd chanted "Kyrie sucks!" and "Where is Kyrie?" It also spent plenty of time serenading Walker with cheers, including "MVP" chants in the fourth quarter.

"I don't really pay attention to the Kyrie stuff," Walker said. "That's just the fans and how they feel. That's not something I'm really paying close attention to. And of course the MVP chants are really great. It's always a great feeling to have support from your fan base, and I most definitely appreciate this fan base."

The teams play again in Brooklyn on Friday afternoon. The Nets haven't said if Irving will return.

"That's why you can't celebrate too much after a win," said Jaylen Brown, who finished with 22 points and 10 rebounds for Boston. "It's always about the next one in this league. We've got to lock in. It's a weird opportunity, to get to play the same team twice, so we've got to be ready for the next game like we are today."