BOSTON — Boston Celtics star Jayson TatumHis belated birthday gift to himself was a return to the game that was abruptly taken from him last season.

Tatum started the Celtics’ 120-100 home win over the Dallas Mavericks on Friday, marking his season debut nearly 10 months after undergoing surgery to repair a torn right Achilles tendon.

Tatum played 27 minutes and scored 15 points.

“It’s been a long journey. And the culmination of a new journey begins today,” coach Joe Mazzulla said during his pregame press conference.

The typical rehabilitation period to return to basketball action after Achilles tendon surgery is nine to 12 months.

Tatum, who underwent surgery on May 13, returned to the court after 298 days.

The Associated Press contributed to this report.