BOSTON, Feb. 28 (Ticker) -- The Boston Celtics were missing Paul Pierce for the first time in more than three years. Fellow All-Star Antoine Walker had no problem picking up the slack.

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Walker collected 22 points, 11 rebounds and nine assists and hit a key basket down the stretch as the Celtics edged the Toronto Raptors, 90-85 in the front end of a home-and-home series.

Rookie J.R. Bremer added 20 points and Eric Williams 18 for the Celtics, who remained one-half game behind Philadelphia for fourth place in the Eastern Conference playoff race. The Celtics had lost three of their previous five contests.

"Without Paul being there, we didn't know what we were going to do in the full-court as far as scoring, but everybody stepped up," Williams said.

Pierce, the NBA's fifth-leading scorer, sat out the contest after slipping on a patch of ice at his home and straining his lower back. He had played in 257 straight games - the third-longest actice streak in the league - since missing a game at Orlando on January 26, 2000.

"We needed everybody to step up tonight," said Bremer, who made 7-of-10 shots, including 5-of-7 from the arc. "And everybody did a great job stepping up. Luckily my shot came back tonight."

"It was just one of those nights," Raptors forward Jerome Williams said. "They were trying to pound the ball down low in terms of getting Eric Williams the ball, (and) he did a great job for them. But Bremer was really able to step it up. He was able to make the open three and put pressure on the outside. So whenever you get into that continuity, with your offense going inside and out, it's going to be a tough night to play defense."

The Celtics scored the last seven points of the third quarter and the first four of the fourth to take a 71-60 lead. They led by 12 points midway through the second half before Toronto closed to 87-85 on a 3-pointer by Alvin Williams with 38 seconds left.

But Walker countered with a step-back jumper with 18 seconds to play, and after Voshon Lenard missed a jumper, Tony Delk capped the scoring by hitting 1-of-2 free throws with 14 seconds left.

"Yeah, it was a big shot, but it was about team tonight," Walker said. "We wanted to get some movement on the offensive end, we wanted everybody to be aggressive. It is tough to make up 35 percent of our offense, which comes from Paul."

Boston shot 45 percent (34-of-76) from the field and limited Toronto to 37 percent (30-of-82). The Raptors are just 2-20 when shooting below 40 percent.

"I didn't think our intensity defensively was up to a high level, then it finally got there," Raptors coach Lenny Wilkens said. "But you've got to have that defensive intensity all game long, otherwise it takes all the energy out of you. Then that energy is going to be spent somewhere else. It came down to the end when we had some good looks, and couldn't convert."

"We played great half-court defense," Eric Williams said. "We got our hands on the ball and that's what our team does. Paul was out and we knew we had to pick it up on the defensive end."

Vince Carter scored 18 points but had just five after halftime for Toronto, which has lost four of six since a four-game winning streak. Antonio Davis added 13 points and 14 rebounds and Jerome Williams 12 and 10 for the Raptors, who host the Celtics at the Air Canada Centre on Sunday.

Carter left the game with 1:27 remaining after Walker collided with the back of his neck as they dived on the floor for a loose ball. He did not return.

"If (Vince) hadn't gotten hurt there, we had some momentum, and we score, then all of a sudden it's real different," Wilkens said. "It was a very tough point in the game to lose him."

"The left side (of the neck) is sore," Carter said. "I just tried to get back up. The pain was so excruciating."