Boston Celtics forward Kevin Garnett (5) pats teammate forward Paul Pierce (34) on the chest after a play against the Miami Heat in the second half of the Eastern Conference Semifinals at the TD Garden in Boston, Massachusetts on May 7, 2011. UPI/Matthew Healey

The C’s aren’t dead yet. In what was definitely a ‘must-win’ Game 3, the Celtics looked like their old selves for most of the game and outscored the Heat 28-15 in the third quarter en route to a 97-81 win in Game 3.

Kevin Garnett and Paul Pierce both struggled in the first two games, but came up big on Saturday. Garnett posted 28 points (on 13-of-20 shooting) and 18 rebounds, while Pierce scored 27 points, hitting 5-of-7 shots from long range.

Most importantly, the Celtics played good defense on Miami’s three stars, who combined for 15-for-41 (37%) shooting from the field. Garnett dominated Chris Bosh, who scored just six points on 1-for-6 shooting.

Keep an eye on Rajon Rondo heading into Game 4. He got tangled up with Dwyane Wade and injured his arm. He went to the locker room and was able to return, but he was clearly favoring it in the second half.