In the Western Conference, the Oklahoma City Thunder also advanced after a 100-97 victory over the Denver Nuggets while the San Antonio Spurs escaped elimination with a 110-103 overtime win against the Memphis Grizzlies.
Reserve Joel Anthony made two free throws to put Miami up by three with 16 seconds left as the Heat narrowly avoided another fourth-quarter meltdown — Philadelphia went on a 10-0 run in the final 82 seconds to win Game Four — to wrap up their best-of-seven series 4-1.
The Heat had allowed a 10-point fourth-quarter lead to be cut to just one on Wednesday but they made nine of their 10 free throws in the final three minutes to ensure they advanced to a second round clash with the Boston Celtics.
“It was very difficult (to finish the series),” Dwyane Wade told reporters after scoring 12 of his game-high 26 points in the fourth quarter. “That team (Philadelphia) is resilient.
“We knew it was going to be that way. That team got us ready for the next round.”
Chris Bosh finished with 22 points and 11 rebounds while LeBron James had 16 points, but it was the 20 points the home team got off the bench from Mario Chalmers that proved vital.
Philadelphia’s starting lineup had dominated their Miami counterparts throughout the series, outscoring them 78-46 before either side made their first substitutions, which continued on Wednesday as they opened an 11-point lead in the first quarter.
Heat coach Erik Spoelstra changed tactics and started the second half with reserves Chalmers and Anthony, with Chalmers’ contribution proving invaluable.
The guard made two of this six three-pointers in the third quarter, one of which began a 7-0 run that helped Miami to a 72-67 lead heading into the final period.
Elton Brand and Andre Iguodala scored 22 points each for the 76ers.
In Oklahoma City, Kevin Durant carried his team with 41 points as the Thunder erased a nine-point deficit in the final four minutes to clinch the series 4-1 and advance to the next round.
The Thunder went on a 9-0 run to tie the game with 1:50 left, then Durant, the NBA’s leading scorer during the regular season, made two free throws to put his team on top 98-97 before adding the clinching jumper.
Denver’s Arron Afflalo missed a three-point attempt as time expired. Afflalo finished with a team-high 15 points and Kenyon Martin added 14 and 10 rebounds for the Nuggets.
The Thunder will meet the Spurs or Grizzlies in the next round after San Antonio’s Gary Neal made a last-second three-point shot to send their game into overtime.
The Spurs then saved their season by scoring the final seven points of the game to prevail 110-103 and reduce their series deficit to 3-2.
Manu Ginobili scored 33 points and Tony Parker added 24 and nine assists.
The Grizzlies, who had shocked the NBA by putting the Westen Conference top-seeds on the brink of elimination, held a 97-94 lead with less than two seconds to go in regulation when Neal made his shot.
Zach Randolph had 26 points and Mike Conley finished with 20 for Memphis.
Game Six is on Friday in Memphis.
