BOSTON -- By early January, Boston Celtics point guard Isaiah Thomas had established his proclivity for big fourth-quarter outputs. Heck, he set a franchise record by scoring 29 points in the final frame of a come-from-behind win over the Miami Heat in late December. Teammates were constantly telling him that the fourth quarter was his time and Thomas embraced the suggestion.

So after hitting a pull-up 3-pointer as part of what would balloon to a 20-point fourth-quarter outburst during a win over the visiting Washington Wizards on Jan. 11, Thomas walked back up the court, started emphatically pointing to his wrist, and repeated a phrase that had been thrown around in Boston's locker room for a while.

"You know what time it is," Thomas shouted at a frenzied TD Garden crowd.

In that moment, Thomas crafted his signature celebration. Jason Terry has his jet wings. James Harden stirs his pot. LeBron James has the silencer. And now Isaiah Thomas tells everyone what time it is.

Fast-forward three weeks and TD Garden is slowly morphing into one gigantic advertisement for Rolex and Omega.

"I didn't [expect it to take off]," Thomas admitted. "I just did it one game and then it just kept going. I have teammates [and] the fans [doing the celebration]. There are signs in the crowd that say it. And everybody on social media always hits me up saying, 'You know what time it is.' So maybe we can trademark it."

Thomas isn't exaggerating -- both about the popularity of his celebration and his curiosity in making the catchphrase part of his brand. TNT showed Celtics rookie Jaylen Brown doing the watch celebration on the Boston bench during Monday's win over the Pistons. Cameras caught Marcus Smart tapping his wrist while waiting to check back into a game. Even Thomas' father did the watch celebration from his courtside seats during a game last month.

Thomas' fourth-quarter scoring outbursts are unlike anything the league has seen since per-quarter tracking started 20 years ago. Thomas is averaging 10.5 points per game in the fourth quarter this season. That's a full point better than Kobe Bryant's record (9.5 points in 2005-06) and would be the most points averaged by a player in any quarter since per-quarter tracking began.

Thomas has scored at least 15 points in the fourth quarter 10 times this season. That's twice as often as his nearest competitor. Thomas has scored 20 points or more in the fourth on four occasions and no other player has done it more than once.

On Thursday, Thomas was named the Eastern Conference Player of the Month for January after leading the NBA in scoring at 32.9 points per game and guiding Boston to a 10-4 record.

Thomas, who is averaging 29.7 points this season, has zoomed up the NBA's scoring leaderboard and now sits behind only Oklahoma City's Russell Westbrook (30.7). No Boston player has ever averaged 30 points per game in a season and Thomas is positioned to make a charge at Larry Bird's franchise scoring record (29.9 points per game during the 1987-88 season).

When Thomas was referenced as a possible MVP candidate a few weeks ago, it came with the asterisk that Westbrook and Harden were a two-horse race with everyone else in the distance. But Boston has surged to the No. 2 spot in the East and now sits just 2.5 games back of the defending champion Cleveland Cavaliers. With the way that Thomas has carried Boston, it seems safe to suggest that he's every bit the MVP candidate as Westbrook and Harden, regardless of how otherworldly their stat lines have been at times.

Thomas is looking for his third consecutive 40-point game. He has scored 40 or more five times in the past 22 games after not reaching that benchmark over his first 388 career games, according to ESPN Stats & Information.

"Sometimes we catch ourselves looking at [Thomas], watching it, and kinda looking like a fan because he's so small and look at what he's doing," Smart said. "You're looking like, 'Wow. I can't believe he did that.' At the end of the game it's like, 'He had how much?' Isaiah works for that and he's a great player."

Thomas ventures back into the national spotlight Friday night when the Celtics host the Los Angeles Lakers (ESPN, 8 p.m.) The two decorated franchises sit tied with 3,252 all-time wins apiece. But this is hardly the Celtics-Lakers rivalry that it used to be, and even Thomas, whose father is an unabashed die-hard Lakers fan, can't help but admit as much.

"As a player, no, it's definitely not as big as it used to be," Thomas said. "It's just been regular games lately. But me growing up and my dad being a Lakers fan, I definitely know about how it used to be."

A year ago, there was some intrigue with it being Bryant's final game in Boston. That night, Thomas got a pregame sitdown with Bryant and came away raving about the advice Bryant offered, something that probably has encouraged Thomas to keep improving his game.

On Friday, Thomas will be the biggest star on the floor. It's the sort of game that -- especially with the Lakers on the tail end of a back-to-back -- the Celtics should control. And it wouldn't be the worst thing for a Boston team that has had to grind to the finish line in many of their games this season to let the "King in the Fourth" get some rare final-frame rest.

No, the only postseason rivalry that the Celtics and Lakers will have any time soon will happen in May at the draft lottery. The Celtics have the right to swap spots with the Brooklyn Nets, who currently own the worst record in basketball by a healthy margin, and the Lakers have plenty of motivation to finish with a top-3 pick because they otherwise convey that pick to the Philadelphia 76ers.

ESPN's Basketball Power Index projects the Nets and Lakers to finish with the two worst records in the league. Brooklyn's pick currently has a 25 percent chance of being the No. 1 pick while the Lakers own a 15 percent chance at the top spot. Thomas, who represented the team on stage at last year's event where Boston came away with the No. 3 selection (Jaylen Brown), could be back up there alongside a member of the Lakers organization.

Or Thomas might be too busy in the playoffs. The Celtics haven't made it out of the first round of the playoffs the past two seasons, but BPI projects the team with a 98.6 percent chance at earning home-court advantage in the first round. After Wednesday's win over Toronto, the question is whether the Celtics can emerge with one of the top spots in the East.

It seems impossible that Thomas can maintain his level of play and yet he started February right where he left off in January, putting up 44 points, including 19 in the fourth quarter, as Boston rallied past the Raptors.

One of the most memorable parts of the night was the anticipatory rumble that occurred when Thomas checked back in with Boston down eight with 10:41 to play. Boston fans almost expected Thomas to work some of his fourth-quarter magic.

Of course they did. They knew what time it was.