O'Neal had 32 points and 12 rebounds to lead the Heat to their fifth straight victory, 97-87 over the Charlotte Bobcats.
Amid speculation the Heat are set to sign fellow center Alonzo Mourning after he agreed with Toronto on a buyout of his contract earlier in the day, O'Neal clogged up the middle, shooting 13-of-21 in powering the Heat to their ninth win in 10 games.
"We should all be so lucky to have a weapon like the big fella," Bobcats coach Bernie Bickerstaff said.
Damon Jones added 22 points despite playing on a sprained ankle for the Heat, who return home to face San Antonio on Sunday in a possible NBA Finals preview.
Emeka Okafor returned for Charlotte after missing five games with a sprained left ankle, only to aggravate the injury and hobble off the court with 5:41 remaining.
He did not return, finishing with 13 points and seven rebounds as the Bobcats lost their fifth straight.
Okafor doesn't believe the injury is as serious as before but was unsure if he would play Sunday in New York.
"I'm walking around right now. The last time I was on crutches," Okafor said.
Charlotte played without 7-foot-1 center Primoz Brezec, who has a bruised left knee, leaving the Bobcats undersized in trying to defend O'Neal.
Melvin Ely, at 6-foot-10, started at center and guarded O'Neal most of the night.
"He makes me look like I don't belong out there," Ely said.
O'Neal had a 3-point play and Jones hit two 3-pointers and a jumper in a 21-6 third-quarter run that erased a 47-43 Charlotte lead.
O'Neal dunked on the first possession after Okafor went out to make it 83-73.
Charlotte cut the lead to 92-88 on Jason Kapono's 3-pointer with 1:49 left, but Jones answered with his sixth 3 of the game on the next possession to put it away.
"A lot of teams come out with a lot of energy and play above their heads. (The Bobcats) did that in the first half," O'Neal said. "I never panic."
Brevin Knight, who did not start after he said he overslept for practice Thursday, had 17 points and five assists for Charlotte, which shot 41 percent.
The Heat, who had topped 100 points in eight straight games, trailed by as many as eight points in the first half and 40-38 at halftime in part thanks to 3-of-14 shooting from the free-throw line.
The two teams combined to make 17-of-42 free throws, the lowest percentage (.405) for two teams combined in NBA history. The previous record was .410 (25-of-61), set by the Los Angeles Lakers and Chicago on Dec. 7, 1968.
"Sometimes they go and sometimes they don't," said O'Neal, who shot 6-of-15 from the line. "It's just the way the ball bounces sometimes."
Bickerstaff said Brezec was getting some ribbing from his teammates for missing the game. "They think he may have Shaq-itis," Bickerstaff said ... Heat coach Stan Van Gundy was surprised Jones was able to play after spraining his ankle in practice Thursday. "He couldn't move around this morning," Van Gundy said ... Heat reserve center Michael Doleac missed the game because of a personal matter ... The attendance of
22,166 was the second-best crowd for the expansion team, behind opening night.
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Within just a few hours of Thursday night's NBA draft, the Oklahoma City Thunder are reportedly shopping Serge Ibaka.
LeBron James made it official Thursday, saying he will not play in this summer's Olympics. Carmelo Anthony, DeAndre Jordan, Jimmy Butler and Klay Thompson are among the players who will.