LeBron James scored 34 points and Dwyane Wade added 23 as Miami withstood a stellar performance by Boston's Rajon Rondo to beat the Celtics 115-111 in overtime in game two of the NBA Eastern Conference finals.
With Wednesday's victory, the Heat took a 2-0 lead in the best-of-seven series that will send the winners into the NBA championship against either San Antonio or Oklahoma City.
Rondo was spectacular for the Celtics, playing all 53 minutes and scoring 44 points with 10 assists and eight rebounds.
But it was not enough against a Heat team that also got 22 points from Mario Chalmers.
Wade scored 21 of his 23 points after half-time. He absorbed a hard foul from Kevin Garnett in overtime, made his shot and then the free-throw for a key three-point play.
The extra period came after NBA Most Valuable Player LeBron James missed two shots in the closing seconds of regulation. Miami responded by scoring nine straight points to seize control in overtime.
Paul Pierce scored 21 points, Kevin Garnett added 18 and Ray Allen 13 for the Celtics, who will try to bounce back on Friday when they host game three of the series.