Haslem added two more big plays down the stretch, hitting a jumper after a scramble to extend Miami's lead to 92-87 with 2:37 remaining, then hitting a pair of free throws with 1:32 left after the Nets had gotten within two.
Wade was 6-of-7 in the first quarter, capping his 12-point period with a jumper with 2.4 seconds left that gave Miami a 27-24 lead. The Heat shot 65 percent (13-for-20) in the first 12 minutes.
But they missed a chance to expand their lead much more with some poor free throw shooting in the second. They missed four of seven during a 4-minute stretch without a field goal, allowing New Jersey to tie it at 44.
Jason Williams made a 3-pointer to break the tie, and Walker added one later in the period as Miami took a 54-48 lead at halftime. The Nets were only 7-of-25 (28 percent) from the field in the second quarter and 37 percent in the first half.
Clippers 114, Suns 107
Sam Cassell loves playing in the fourth quarter, and wants the ball when the game is on the line.
After spending only 35 seconds on the court in the final period of Game 3 in the Western Conference semifinals, the 36-year-old point guard knew he'd get an opportunity in Game 4.
He got his shot, all right, and buried the Phoenix Suns.
Cassell made two 3-pointers down the stretch, including the clincher with 27 seconds left, and the Los Angeles Clippers beat the Suns 114-107 to even the best-of-seven series 2-2.
Game 5 is tonight in Phoenix.
Cassell played only 35 seconds in the final period two nights earlier, when the Suns edged the Clippers 94-91.
Coach Mike Dunleavy has said repeatedly since then that he didn't second-guess that decision, and Cassell concurred.
"I'm going to be a head coach in this league some day. Coaching is a feel," Cassell said. "I don't blame Coach Dunleavy. I knew in Game 4 I was going to be in the fourth quarter a lot. I didn't even worry about Game 3."
Cassell began the final period on the bench, but returned with 7:19 to play.
Cassell, who entered the postseason with more playoff experience than the rest of his teammates combined, finished with 28 points, 11 rebounds and nine assists.
He scored only six points in Game 3, when he was usually guarded by the taller Shawn Marion. It didn't seem to matter who defended Cassell in this game, especially in the second half, when he scored 18 points.
Three-pointers by Vladimir Radmanovic and Cassell gave the Clippers what appeared to be a safe 106-93 lead with 5:54 remaining. The Suns then scored 12 straight points to move within one before Elton Brand made an 18-foot jumper with 56 seconds remaining and, after Tim Thomas missed a 3-pointer, Cassell hit his big shot.
"Last year, we would have lost at the end," said Brand, who had 30 points, nine rebounds and eight assists. "Sam brings swagger, Sam brought swagger tonight. We need to have it every game."
The Clippers won without starting center Chris Kaman, sidelined because of a sore right shoulder. Kaman, injured in Game 3, suited up and was available, according to a team spokesman, but never left the bench.
But the Clippers won anyway.
"Sam Cassell hit the big shots down the stretch," Suns coach Mike D'Antoni said. "Sam can get off on anybody. Sam's been around for a long time."