The Hawks-Celtics rivalry – and Dennis Schroder versus Isaiah Thomas in particular – has risen to a new level.

The two point guards intensified a rivalry between the teams with a slap confrontation during last season’s playoff series, won by the Hawks in six games. This summer, long-time Hawks center Al Horford signed with the Celtics as an unrestricted free agent. Horford was booed much of the night whenever he touched the ball.

Enough drama?

When the Celtics went up by 20 points in the third quarter, Thomas went to the bench and taunted the Philips Arena crowd by repeatedly yelling that Schroder “ain’t nothing.”

Stay tuned. There are two more games between the teams this season.

“I’m playing basketball,” Schroder said. “If he think that he got to curse at my mom or say some dumb stuff about my family, that has nothing to do with basketball. That’s his choice. I’ve got too much class for that. Next one, we are going to get it.”

The Hawks erased the deficit but it was Thomas who scored in the final seconds to give the Celtics a 103-101 win at Philips Arena.

The Hawks (22-17) had a seven-game win streak snapped and lost for just the fifth time in the past 17 games.

Mike Dunleavy hit a corner 3-pointer, his second of the game, to pull the Hawks within two points, 94-92, with 2:11 remaining. Kelly Olynyk hit a pair of free throws and Thomas scored to put the Celtics up by six. Malcolm Delaney hit a 3-pointer to make it a one-possession game. However, Thomas answered with a 3-pointer with 52.4 seconds left to regain the advantage.

The Hawks weren’t done.

Tim Hardaway Jr. and Paul Millsap hit back to back 3-pointers to tie the game at 101-101 with 25.6 seconds left.

Thomas scored with 2.4 seconds left for the game winner. Millsap missed at the buzzer to end the Hawks’ comeback.

Millsap and Hardaway had 23 points each for the Hawks, who made their late run with Dwight Howard and Schroder on the bench.

The Celtics (25-15) were led by Thomas with 28 points. Olynyk had a season-high 26 points and Horford had 10 points, six rebounds, six assists, a steal and a block.

The Celtics led by as many as 15 points in the first quarter. They used a 20-2 run on the strength of a 3-point barrage to lead 25-10. Eight of the Celtics’ nine field goals during the run were 3-pointers as they went 8 of 12 from long range in the opening quarter.

The Celtics would miss their next eight from long range and the Hawks erased the deficit to tie the game at 42-42 on a pair of Millsap free throws. However, the Celtics would make two more 3-pointers and take a 48-44 lead into intermission.

The Celtics hit five more 3-pointers in the third quarter and outscored the Hawks 30-21 in the period. They took the 20-point edge for the comfortable margin. For a while, anyway.