"That's tough to win that way against Boston because those guys are going to get shots," Pistons coach Michael Curry said.
Rivers said Detroit is going through a tough stretch because its still adjusting to the radical change of adding Iverson in exchange for All-Star point guard Chauncey Billups.
"They'll be as dangerous as anybody in the playoffs," Rivers said. "That's what I know for sure."
In a rematch of the Eastern Conference finals, tempers flared with 5:56 left in the game.
Boston's Kendrick Perkins was ejected after being called for a flagrant foul following a video review that showed he knocked Jason Maxiell down to the court with a hard foul.
"I didn't want to give up a layup, so I was trying to foul him hard across the arms, but he ducked his head and I got him on the neck," Perkins said. "I wasn't trying to hurt him. I don't do that"
Maxiell responded with a shove and was called for a technical.
After the game was stopped for free throws, Hamilton made a shot to make it 71-67. Then the Celtics scored seven straight points to seal the victory.
The Celtics paved the way for the win by jumping out to a 12-4 lead and scoring eight of the first nine points after halftime.
"You can't allow teams to go on runs like that," Curry said.
The Pistons rallied in the second and fourth quarters and got within three midway through the final quarter, but Garnett's jumper capped a 10-2 run that gave the Celtics an 11-point lead.
"We played good in spurts, but with a team that is good, experienced and won a championship that's just not good enough," Iverson said. "You have to play well the whole game."
The Pistons honored Kid Rock for selling out 18 concerts, putting a banner to the rafters with his name in a tribute also earned by Neil Diamond, Bon Jovi and Alan Jackson. ... Boston was without F Brian Scalabrine (concussion) and doesn't know when he will return. ... Detroit has wins against five of the NBA's six division leaders, beating the Western Conference's top teams on the road, but are 0-3 against Boston. ... Only Phoenix's Shaquille O'Neal has more points among active players than Iverson. ... The Pistons host Cleveland on Sunday. ... Rivers said he was disappointed Allen wasn't selected as an All-Star reserve. "He's the most efficient 2-guard in the league scoring-wise," Rivers said. "The good side of it is Ray gets to golf and relax." ... Curry said he didn't plan to start Kwame Brown again. "That experiment is over," Curry said. Detroit is 9-9 with the former No. 1 pick in the starting lineup.