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.