Celtics beat Heat, one win from NBA Finals KG, Pierce lead Boston, which wins Game 5 thriller on road to take surprising 3-2 series lead MIAMI - Paul Pierce watched the shot sail just over LeBron James' outstretched arm. And when it swished, he turned toward the Boston bench, shaking his head. The biggest shot of the night, for certain. And it put the Miami Heat in big trouble in these Eastern Conference finals. Kevin Garnett finished with 26 points and 11 rebounds, Pierce scored 19 and the Celtics moved one win away from the East title by beating the Heat 94-90 on Tuesday night, taking a 3-2 lead in the series. James finished with 30 points and 13 rebounds for Miami, though he went 8 minutes without scoring in the final quarter. Dwyane Wade scored 27 for the Heat, who got no more than nine from anyone else. Pierce's 3-pointer with 53 seconds left put Boston up 90-86. Miami got within two points twice, and argued that it should have had a steal with 8.8 seconds left. Instead, a foul was called on Udonis Haslem, Garnett made two free throws, and the Celtics knew they had just stolen one on Miami's home floor. Game 6 is Thursday night in Boston, where the Celtics will try to clinch a trip to either Oklahoma City or San Antonio for Game 1 of the NBA finals. The title series starts June 12. The Celtics were down by 13 points in the second quarter, then down nine in the third, and answered both times - prevailing on a night where they shot just 41 percent, and got outrebounded 49-39. Ray Allen and Mickael Pietrus scored 13 apiece for the Celtics, who got 10 from Brandon Bass. The Celtics came into Tuesday a perfect 8-0 in this situation - a Game 5 with series tied at 2-2 - with the core of Pierce, Garnett, Rondo and Allen. And some of James' most memorable moments have come in Game 5s, like the epic 48 points where he just carried Cleveland on every possession down the stretch at Detroit in 2007, and the 120-88 loss to the Celtics in 2010, his last home game with the Cavaliers. This one offered more theater, of course. James hit a 3-pointer to give Miami a two-point lead with 8:10 left, closed out on Pierce to force an airball on the next possession, and eventually Miami pushed the margin out to 78-72 on a layup by Wade with 6:17 to play. On that play, James looked gassed, gasping for air as he stood near the baseline. Those might have been the last gasps the Miami home crowd sees this season. Boston closed on a 22-12 run. Boston tied the game twice early in the third quarter, before Miami peeled off nine straight points to go up 59-50. Four players scored for the Heat during that quick burst, highlighted by Shane Battier's corner 3-pointer and a lazy turnover from Rondo, who threw the ball into the backcourt without being pressured by any Miami defender. But just as they did in the first half when Miami looked poised to pull away, the Celtics rallied - and then some. A 15-1 run gave the Celtics a truckload of momentum going into the fourth. Garnett's dunk while being fouled by James Jones with 1:32 left tied it at 60-all, and Pietrus' long jumper on the next Boston possession gave the Celtics their first lead of the night. The Heat shot 35 percent in the quarter, and Boston took a 65-60 lead into the final 12 minutes after Keyon Dooling connected on a 3-pointer from near the Miami bench with 2 seconds left. So another Game 5, another classic show. Given that it was the Celtics on one side and James on the other, few would have expected anything less. Garnett's jumper with 2:54 left put the Celtics back on top, and Mario Chalmers was assessed a technical foul after the play when referee Derrick Stafford whistled him for pushing Pietrus. Allen made the free throw for an 82-80 lead - but Chalmers, as if to atone, hit a 3-pointer on the next Miami possession for one lead change, followed immediately by another when Pietrus made a 3 at the other end. Wade tied it at 85 with an acrobatic layup with 1:39 to play, but Miami never led again. Miami didn't lead by more than eight points at any time in the three previous games of the series. The Heat changed that quickly, and maybe it was fitting that Chris Bosh got them their first double-digit advantage since Game 1. Bosh came off the bench for his first minutes since straining a lower abdominal muscle in Game 1 of Miami's second-round series against Indiana. His three-point play with 1:17 left in the opening quarter - punctuated with a stare-down for some cheering fans - capped a 24-13 Miami run to open the game. James made a 3-pointer with 9:39 left in the half, and the Heat went up 31-18. The Celtics did what Miami did to them in Games 3 and 4 at Boston. They started chipping away. Miami missed 15 of its final 17 shots of the first half, with four turnovers thrown in there as well, and the Celtics took advantage. After James' 3-pointer, Boston outscored Miami 22-11 to close the second quarter - Garnett got six of his eight first-half points in the final 3:09 - and the once-sizable Heat lead was down to 42-40 by intermission. NOTES: Dorell Wright, a member of the 2006 Heat championship team and now with Golden State, was in attendance. A denim-vested Amare Stoudemire of the New York Knicks - Miami's first-round playoff foe - was seated courtside, and former Celtic Glen Davis was near the Boston bench. ... Wade scored seven points in the first 4:22 of the game. He didn't score again in the first half, and after scoring 26 points by halftime of the series-clincher against Indiana, he has 29 points in five first halves against Boston in this series. ... Pierce said before the game that he does not expect to need offseason surgery to repair the sprained MCL in his left knee. "No complaints," Pierce said.