Ex-Celtic Grant Williams is sent off after an unnecessarily hard foul on Jayson Tatum

Boston Celtics star Jayson Tatum and Grant Williams share a close friendship.

Things didn't look that way at the end of Boston's 124-109 victory over the Charlotte Hornets on Friday night at the Spectrum Center.

Williams tried to stop Tatum in transition with 2:02 left in the fourth quarter, but instead of committing a harmless foul, the former Celtics forward committed one intentionally ran over the five-time All-Star. The hard collision caused both Williams and Tatum to fall to the ground.

The play was reviewed by the officiating team and ruled a blatant 2, resulting in Williams being ejected. For Williams it was the fifth exit in his career.

Tatum didn't respond to Williams' cheap shot, but Jaylen Brown had something to say to his former teammate. Brown confronted Williams while he was still on the ground before the two sides were separated.

It's unclear why Williams committed such an unnecessary foul, especially on someone he had a close bond with during his four seasons with the Celtics.

Tatum, who picked up another flagrant foul seconds later when LaMelo Ball shot into his landing zone, got the last laugh by finishing with a game-high 32 points on 9-for-19 shooting to go with 11 rebounds, three assists and three steals. Williams had just six points and seven rebounds in 30 minutes.

The matchup between Tatum and Williams will certainly make things interesting on Saturday when the Celtics and Hornets meet against the Spectrum Center.