Allen's three-pointer with 34.3 seconds left tied the game at 99-all. James missed two shots, first a layup - he got the rebound of his own miss - and then a jumper on the final possession of regulation, and to overtime they went.
The Heat had come back from 14 points down in Game 6 of the 2006 NBA Finals.
And this one was slipping away, more than once. James also two free throws 21 seconds into overtime, and Miami looked in trouble.
The scoring dossier in overtime began like this: Rondo scored, Heat tied it, Rondo scored, Heat tied it, Rondo scored, Heat tied it.
When Rondo missed a layup with 1 minute, 33 seconds left, Miami took advantage, with Udonis Haslem getting a dunk to put the Heat up, 105-103. And after a turnover on the next Boston possession, Wade drove the lane, hit the deck and watched as his layup bounced on the rim and dropped through.
Garnett stood over Wade and glared, to no avail. Wade hit the free throw, and Miami was up 110-105 with 59.7 seconds left.
On a night where the Heat missed 16 free throws - including at least four by James in crucial situations - they would survive.
Gregg Popovich implored his San Antonio Spurs to get nasty to take control of the Western Conference finals.
The Oklahoma City Thunder may just have to get ugly if they hope to make it a series.
The Thunder have struggled to corral a San Antonio offense that is clicking on all cylinders during a 20-game winning streak, the longest any NBA team has been able to maintain into the playoffs.
Oklahoma City is in a two-games-to-none hole as the series shifts to the Chesapeake Energy Arena in Oklahoma City for Game 3 on Thursday night. Maybe - just maybe - the Thunder found something that works while trying to rally from a 22-point, third-quarter deficit in Game 2.
They toughened up, turned it into a more physical contest, and the NBA's best free-throw shooting team had both teams marching to the foul line as the lead shrank to six. The Spurs were able to close it out for a 120-111 victory Tuesday night in San Antonio.
"We're a physical team. We have to play that way," Thunder coach Scott Brooks said Wednesday. "If we play free-flowing basketball, we can beat some teams, but we're not at our best if we're not being physical on the defensive end.
- Associated Press