BOSTON -- In the middle of Isaiah Thomas' latest fourth-quarter outburst, the TNT broadcast cut to a shot of the Boston Celtics bench celebrating one of his baskets. Rookie Jaylen Brown turned toward the sideline camera and pointed at his wrist -- a now-familiar sequence that reminds everyone that the fourth quarter belongs to Thomas.

Just when it seems impossible that Thomas could maintain his recent level of late-game play, he responds with another monster effort. On Monday, Thomas scored 24 of his game-high 41 points in the fourth quarter as Boston escaped with a 113-109 triumph over the visiting Detroit Pistons at TD Garden.

"He amazes me, for sure. Since I’ve been a part of this team, I’ve been completely amazed," said Brown, the No. 3 pick in the 2016 draft. "I mean, I knew he was a good basketball player, but it’s written in stone now. He’s starting his own legacy. He’s one of the best players in the NBA this year, hands down. It’s undebatable now. All-Star, MVP candidate. It doesn’t get much better than that."

Like the rest of the NBA, the Pistons could not keep up with Isaiah Thomas in the fourth quarter Monday, as he scored 24 of his 41 points. Brian Babineau/NBAE via Getty Images

Brown has been elevated to a starting role recently with Avery Bradley sidelined by an Achilles injury, but the rookie was fine with simply having a front-row seat for Thomas' latest fourth-quarter shenanigans. Thomas connected on 6 of 9 shots in the final frame, including a trio of 3-pointers, while playing all 12 minutes. After Detroit rallied from 11 points down to surge ahead midway through the quarter, Thomas responded with 9 points in 100 seconds. Boston never trailed again.

"We look for him in the fourth quarter," Brown said. "He’s that type of player. He likes that pressure, he likes those type of moments."

It's getting hard to keep up with all the ridiculous numbers that Thomas is putting up late in games. He is now nearly a full point ahead of Russell Westbrook in leading the league with an average of 10.3 points in fourth quarters. If that holds, it would be the highest average in the 20 years that the NBA has tracked by-quarter scoring.

Thomas has also scored 20 points or more in 32 straight games. That's the second-longest streak in team history. Thomas is chasing John Havlicek's record of 40 straight, having recently zoomed past Kevin McHale, who was broadcasting Monday's game for TNT. Thomas has scored 20 points or more in all but one of his 44 games this season.

Thomas would have needed 50 points on Monday to leapfrog Paul Pierce and Larry Bird and emerge as the top scorer in a month in franchise history. In coming up a bit short, Thomas settled for fourth place -- an appropriate number considering his jersey number and fourth-quarter exploits -- at 32.9 points per game. Only Pierce (33.5 points per game in February 2006) and Bird (33.3 in April 1987 and 33.1 in February 1998) have produced higher-scoring months.

Thomas acknowledged he had heard rumbles on social media about the possibility of him catching the Celtics legends, and he marveled at simply putting his name near theirs. "That doesn’t even seem real. It doesn’t sound real," Thomas said. "So many great players who did it before me, to have my name up there with those legends is unbelievable. I’m going to just keep going, keep trying to catch those guys, and keep winning."

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Thomas enters the final day of January averaging 4.3 more points per game than his nearest Eastern Conference competitor this month (DeMar DeRozan, 28.6). Thomas, who was nominated for Eastern Conference Player of the Week for the sixth straight week on Monday, got passed over for a fifth time when Miami's Dion Waiters emerged with the honor. Thomas should be in line to take home the East Player of the Month award for January.

Celtics coach Brad Stevens was asked if there's anything Thomas can do that would surprise him, and Stevens acknowledged his guard has simply been otherworldly lately. "[Detroit] kind of kept us off-balance with their coverages, and so we just tried to get him off the ball some," Stevens said. "And then when he got going late, he just got going, so it didn't matter if he was off the ball or on the ball. He was unbelievable."

Pistons coach Stan Van Gundy blamed himself for not finding a way to better corral Thomas and wondered if he should have sent more bodies at him. Van Gundy shouldn't lose too much sleep over it, though, because Thomas has been doing this to every opponent.

Told that the Pistons were doing a good job defending him for the first three quarters, Thomas playfully joked: "They was? No, I’m just playing. I’m just playing. Like I always say, I just tried to be a little more aggressive to score and make plays. And things started to open up."

The Celtics (30-18) have won four straight and sit in second place in the East with a one-game lead over the Toronto Raptors, who visit TD Garden on Wednesday night. A victory would put Stevens in position to coach the East All-Stars in New Orleans next month, and Thomas likes that possibility because it could mean more playing time for him as an All-Star reserve. "I will [play more], I know that. So we have to get him there," Thomas said. "Hopefully we can sneak him in there."

For all their success this season, the Celtics had fizzled on national TV this season before Monday. They were 0-3 in previous games on TNT and just 3-5 overall on national TV. Monday's game was the first of three national games in the next seven days, with games against the Lakers and Clippers set to keep Thomas and Co. in the spotlight.

That will give the rest of the nation a better glimpse of what Thomas has been doing lately. This was his fourth 20-point fourth quarter this season, and compared to others -- such as a 29-point, franchise-record outburst against Miami in late December -- his one seemed relatively normal, even though no other player in the NBA has reached that 20-point, fourth-quarter benchmark more than once this season.

Through it all, Thomas is simply happy that Boston is starting to play more consistent defense and winning games.

"Playing harder -- I think that’s the biggest key for us," Thomas said. "We’re into guys, defensively. We’re playing with energy and getting back to our old ways. We gotta continue to build on that. We’re not where we want to be, but we’re headed in that direction. We just gotta keep focusing and lock in on what we need to do."