CHICAGO, Dec. 8 (Ticker) -- Ron Mercer hit a turnaround jumper to snap a tie with 1:24 remaining and added a free throw with 7.2 seconds left as the lowly Chicago Bulls ended the Boston Celtics' season-high six-game winning streak with an 87-84 truimph.

Boston had a chance to tie, but Paul Pierce's 3-pointer came up short and Charles Oakley handed the rebound to Greg Anthony to seal the victory.

The Celtics led, 55-39, after Antoine Walker hit a 3-pointer with 9:55 to play in the third quarter. But the Bulls came back to tie it at 70-70 entering the final period.

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Chicago took its first lead of the game, 83-82, on a free throw by Marcus Fizer with 3:13 to go. After Fizer made his second shot from the line, Boston's Eric Williams hit a short jumper while falling after being fouled to tie it.

Williams missed the ensuing free throw with 2:40 left, Mercer broke the tie with his jumper and Boston did not score thereafter.

"Boston has been playing better than anyone in the league of late," Bulls coach Tim Floyd said. "They won six in a row, three on the road, and this is our fourth game in five days for our club, so it was a nice win."

The Bulls, who had a 56-42 rebounding edge, placed six players in double figures. Brad Miller led the way with 20 points and 16 rebounds and Anthony added 14 points, five rebounds and five assists.

"We held them down defensively and we made some of our shots, especially in the third quarter," Miller said. Pierce was in foul trouble and any time you can keep him off the court it is a huge bonus."

Walker had 27 points, including 7-of-10 3-pointers to tie a United Center record, and 10 boards for Boston, which also got 12 points on 4-of-15 shooting from Pierce.

"They just played aggressive and wanted it more down the stretch than us," Walker said. "Once they got back in the game, it became a possession game. Mercer then hit that big shot. We just had a lull in the third quarter and then they played well. Defensively we played well in the fourth quarter but couldn't score."

Boston made 11-of-19 from the arc while Chicago made just 3-of-13. But the Bulls made 30-of-37 from the line, and the Celtics converted just 9-of-18 free throws.

Neither team shot well overall. Both teams made just 32 percent of their shots, with Boston hitting just 32-of-86 shots and Chicago only 27-of-73.

"Their best effort was just better than ours," Celtics coach Jim O'Brien said. "They took us out of our game plan. They wouldn't let Paul get the ball in the low post. If we didn't get the threes like we did, we'd be talking about a 20-point loss."

Chicago snapped a three-game losing streak against Boston and avenged a 96-82 road defeat on November 2.

"It's very frustrating," Williams said. "We had a great opportunity to get this game, instead it's a major letdown. We weren't active defensively the way we were the last two weeks. We tried to coast after we were up 15, and that's how they beat us."