CELTICS 101, 76ERS 85: Brandon Bass scored 18 of his career playoff-best 27 points in the third quarter to help host Boston take a 3-2 lead in the Eastern Conference second-round series.

Kevin Garnett added 20 points, Paul Pierce scored 16 points and Rajon Rondo had 13 points and 14 assists as the Celtics moved within one victory of winning the best-of-seven series.

Elton Brand scored 19 points for Philadelphia.

Game 6 is Wednesday in Philadelphia.

Bass outscored the 76ers by himself in the decisive third quarter as Boston shot 61.1 percent from the field to turn a three-point halftime deficit into a 75-66 lead.

Bass, who was 6-of-7 shooting in the quarter, tied the contest at 57 by sinking two free throws with 6:37 left during a sequence in which he scored 12 of Boston’s 14 points. Greg Stiemsma followed with a dunk to give Boston a 71-64 lead and Pierce capped the impressive quarter with a jumper with 2.6 seconds left as Boston took a nine-point lead.

The Celtics then scored the first six points of the final quarter to boost their lead to 81-66 with 9:15 remaining. The lead reached 91-72 on a dunk by Mickael Pietrus with 4:20 to play and topped out at 20.

Lavoy Allen scored 12 points on 6-of-6 shooting for the 76ers.

Philadelphia never trailed over the final 16-plus minutes of the first half. The 76ers shot 54.8 percent from the field en route to a 50-47 halftime lead and received 12 points from Brand.

GAME NOTEBOOK: Boston guard Avery Bradley (shoulder) missed the contest and Ray Allen started in his place. … Brand had just 17 points in the first four games of the series. … The Celtics hit 26 of 33 free throws while the 76ers were just 10 of 16. … Sixers guard Lou Williams connected on just 3 of 10 shots and is a porous 10 of 34 from the field in the three playoff games in Boston.