The Celtics (20-3) had matched their best start ever, also achieved by the 1963-64 team that won the NBA title.
Billups, who scored 12 of his team-high 28 points in the final quarter, was fouled by Tony Allen in a matchup of the Eastern Conference's top teams.
"It was playoff-intense, pretty aggressive out there," Pistons coach Flip Saunders said.
Bulls 95, Wizards 84 -- Ben Gordon scored 22 points and Chicago had a 12-0 run in the final four minutes to beat host Washington. Chicago's run came after Caron Butler's jump shot gave Washington its first lead of the second half, 80-79, with about four minutes to play. The Bulls scored the game's next 12 points to secure the win.
Mavericks 108, Suns 105 -- Dirk Nowitzki scored 31 points, including the Mavericks' final eight, giving Dallas just enough to hold off Phoenix in another intense, entertaining game between the Western Conference rivals.
Warriors 111, Timberwolves 98 -- Al Harrington scored 25 points, including 14 in the decisive third quarter, and Golden State ran past host Minnesota during another second-half fade by the Timberwolves.
Magic 97, Rockets 92 -- Dwight Howard had 21 points, 11 rebounds and three blocks, and visiting Orlando took advantage of Tracy McGrady's absence in the second half to beat Houston. McGrady left with a sore left knee after going 1-for-10 from the field in the first half.
Kings 102, Bucks 89 -- Ron Artest scored 26 points and had eight assists, and Beno Udrih hit a career-high six three-pointers to help Sacramento beat Milwaukee to finish 3-2 on its five-game road trip.
Hornets 107, SuperSonics 93 -- Chris Paul scored 21 points and had 15 assists, and Morris Peterson matched a career high with seven three-pointers and finished with 25 points to help New Orleans beat Seattle.
20 -- Double doubles by Chris Kaman this season as of Tuesday's game, in which he had 12 points and 16 rebounds in the Clippers' loss.