The Pistons got off to a lackadaisical start, falling behind by double digits in the first 10 minutes, and couldn't dig themselves out, losing 83-82.
"We were terrible," Pistons coach Flip Saunders said. "The score isn't reflective of the way we played - we shouldn't have only lost this game by one point."
The Sixers didn't score in the final 2:27, missing their final five shots, but won when Chauncey Billups' jumper over Rodney Carney bounced off the rim as time expired.
"It's a big win," said Andre Iguodala, who led all scorers with 22 points. "It's on the road, and we didn't shoot the ball well down the stretch, but we pulled it out because we got some stops. That's what makes it big."
Carney jumped into the play when Billups tried to pump-fake Lou Williams.
"I tried to rock and get him off-balance, but they came at me with the double-team," Billups said. "I didn't think there was enough time to get the ball to anyone else, so I had to shoot it. I got a pretty good look, but that's not the shot I want to take in that situation."
Carney scored 16 points for Philadelphia, and Samuel Dalembert grabbed 15 rebounds as the Sixers won two days after a 14-point home loss to the Eastern Conference's other power, Boston.
"We talked about that - playing two of the top teams in the East and coming out 1-1," Philadelphia coach Maurice Cheeks said.
"We feel pretty good about that."
Detroit, normally the NBA's best team at taking care of the ball, committed 15 turnovers and only had 15 assists.
"If we turn the ball over like that, we can't beat anyone," Saunders said.
The Pistons led 67-66 going into the fourth, but Philadelphia got the first two baskets of the period to go up by three with 9:35 left. Detroit came back with six straight points, including two dunks by Jason Maxiell, before the Sixers rallied again.
This time, it was five points from Iguodala - all from the free-throw line - that helped Philadelphia build a 77-73 lead with 5:52 to go.
"This wasn't one guy making it happen - everyone stepped up," Iguodala said. "We didn't panic, we knew that if we didn't score, we had to get a stop. That shows how we have matured over the season."
Detroit didn't help itself by missing three straight free throws, including two by Richard Hamilton, an 83 percent shooter.
"When you shoot that badly from the line, you start to think the team's mind isn't in the game" Saunders said.
Philadelphia had two chances to clinch the game, but Iguodala missed an open jumper and Reggie Evans was blocked by McDyess. After two missed free throws by Hamilton, the Pistons got another stop, keeping them within 83-80 with 32 seconds left.
Iguodala missed again, and Wallace grabbed the rebound with 3.9 seconds left. Cheeks argued that Wallace dribbled the ball before calling timeout, but Detroit was allowed to take the ball at midcourt. Billups took the inbounds pass, but was blocked when he tried to drive, and had to take a tough 18-footer over Carney as time ran out.
The Sixers led by as many as 12 in the first half, and still had a 48-42 edge at the break. Iguodala had 14 points in the half, while Evans had nine points and nine rebounds.
"I told our starters that when they play that badly with that little energy, it really puts our bench in a tough position," Saunders said.
Detroit, though, started the third quarter with an 21-9 run to take a 63-57 lead. Wallace, Hamilton and Tayshaun Prince scored five points each in the run and McDyess added four.
Notes:
Wallace returned after missing two games with a sprained
left ankle. ... Evans replaced Carney in the starting lineup as
Philadelphia went with a bigger group. ... Andre Miller left the
game in the fourth quarter with a lower-back strain and is
day-to-day.
