Golden State began the trip with a 108-98 win over Toronto on Friday, but has since lost two straight, including a 109-98 defeat to Boston on Monday.
Troy Murphy had 27 points and 12 rebounds for the Warriors, who have lost five of seven following a season-high five-game win streak. Murphy scored 13 points in the third quarter, including 10 in a 20-8 spurt that erased an 11-point Celtics lead.
Murphy completed a three-point play to pull the Warriors within 93-88 in the fourth, but the Celtics scored 10 of the next 12 points to put the game away.
Golden State has allowed its opponent to score 25 or more points in the first quarter six times over the last seven games.
“We’re giving up too many points to start the game,” Warriors point guard Derek Fisher said. “We’re having to work so hard to stay in games. At that point you know we may be unable to finish games better than we could be if we didn’t have to work so hard to fight back from 10 down, 12 down … it takes a lot of energy.”
Golden State concludes its trip Friday against Detroit.
The Sixers won for the fifth time in six games Sunday behind the play of Andre Iguodala, who matched his career high with 26 points in a 107-80 victory over the Raptors.
Iguodala recorded his other 26-point performance in Toronto on Nov. 16.
“I feel comfortable in this gym,” said Iguodala, who went 9-for-10 from the field and added five assists. “The crowd really embraces me when I come here. It’s kind of funny being on the road.”
He had 13 points in the third quarter, including four dunks in the Sixers’ 21-4 run to open the period.
“It was the second game in row he had a magnificent game up here,” Philadelphia coach Maurice Cheeks said. “He, again, was instrumental in getting into the open court and getting easy baskets.”
Golden State has won five of its last eight over Philadelphia after losing the previous six meetings in the series.