Wade also grabbed 10 rebounds and had eight assists, while O’Neal tallied 10 points and grabbed 11 boards before fouling out in his first action since November 3. He sprained his right ankle during the second game of the season versus Indiana and had been out ever since.
Gary Payton scored a season-high 21 points and Udonis Haslem chipped in 11 points and eight boards for Miami, which snapped a four-game losing streak.
Alonzo Mourning started at center instead of O’Neal, who entered the game with 5:55 remaining in the first period to a standing ovation.
"Alonzo is playing well right now," O’Neal said. "I really don’t have my timing back, so I did not really want to mess anybody up. It doesn’t matter who starts and who comes off the bench. When I get my wind back and when I get cleared to play 48 minutes, then I will start."
Caron Butler tallied a season-high 28 points and pulled down 10 rebounds, Chucky Atkins scored a season-high 26 points, both off the bench, and Gilbert Arenas contributed 24 points in the loss.
Antawn Jamison grabbed 11 rebounds despite struggling from the floor (3-of-17) for the Wizards, who have lost three in a row.
O’Neal scored the first three points of overtime, including an emphatic slam. Atkins responded with a trey to tie the game at 98-98 almost two minutes into the extra session.
Wade followed an O’Neal miss with a layup to give Miami the two-point edge. O’Neal fouled out with 1:33 remaining, but Wade converted another layup with under a minute left to put Miami up 102-98.
Atkins buried a trey, his sixth of the game, to trim the deficit to 102-101 with under a second remaining. Wade drained two free throws on the other end, and Jamison’s three-pointer missed well wide as time expired.
"It felt good to have Shaq back," Wade said. "We are bringing him back slowly because we are going to need him on this long road trip. Guys on our team need to continue to step it up as a team."
The Heat start a four-game road trip Tuesday night at Chicago.
The game was tight down the stretch and sending the game into overtime rested on the foul shooting of O’Neal, who ended the game 6-of-16 at the free throw line and 2-of-7 from the field.
Trailing 88-80, the Wizards scored the next nine points to take the lead. Atkins scored five points and Butler tallied four, including the go-ahead layup with just over five minutes to go.
With just over 1 1/2 minutes left and the game tied at 91-91, Butler drained a jumper to give Washington the lead. After Arenas made 1-of-2 from the charity stripe a few moments later, Wade attacked the basket, but missed in close and Michael Ruffin converted 1-of-2 free throws to give the Wizards a two-possession advantage, 95-91, with just over 47 seconds to go.
"With Dwyane, you almost have to have three defenders," said Wizards head coach Eddie Jordan.
Payton drained a trey from the right corner on the next possession to cut the deficit to 95-94.
Haslem blocked Brendan Haywood’s shot on the other end, and O’Neal was fouled with one second to play. He made 1-of-2 foul shots to send the game to overtime.
Both teams got off to a sluggish start and Miami held a 21-18 lead after the first quarter. With the game tied at 33-33, Washington went a 13-5 spurt to take an eight-point lead.
Atkins was the catalyst of the scoring streak with eight points, including two deep three-pointers. Atkins converted a layup, then Butler made a lay-in that gave Washington a 48-38 advantage with around two minutes left in the half.
The Wizards took a 48-42 lead into the locker room.
Miami started the third quarter on an 11-4 run to take a 53-52 lead. Payton scored five of the points and Wade gave Miami the lead on a short jumper with around 9 1/2 minutes to go.
The lead went back-and-forth for the rest of the period and the Heat took a 77-72 lead into the fourth stanza.
Game Notes
Miami has won nine straight meetings with the Wizards...The Heat are 8-3 at home this season...Washington is 3-7 away from the MCI Center this season...Miami shot 42.2 percent from the floor, while Washington made 38.7 percent of its shots.
Miami Heat 
Washington Wizards 
