“I can imagine right now that Kevin Garnett and Paul Pierce and these guys are in there right now saying let’s deliver the knockout punch today. This game, I think they feel like, if they beat us they can knock us out.” — Philadelphia coach Doug Collins an hour before tip-off.

The Celtics didn’t win the Atlantic Division on Sunday with a 103-79 blowout win over the 76ers, but they did deliver a decisive blow to their reeling rivals. Whether Philly gets up off the mat is up to them, but with two and a half weeks left in the regular season the Celtics suddenly have a three-game lead in the division and the Sixers are tied for the final playoff spot with the Knicks, just a game ahead of the Bucks.

WHAT WENT RIGHT

Ray Allen as the microwave: For most of the season the first four minutes of the second quarter have been a time for Celtics fans to make a sandwich, pay some bills or maybe change the oil in the car. Anything but watch them struggle through ugly, scoreless basketball. That’s changed now that Ray Allen is doing his work off the bench. Allen scored eight points in his first nine minutes of playing time on 3-for-4 shooting and the lineup of Allen and Kevin Garnett along with Avery Bradley, Sasha Pavlovic and Greg Stiemsma outscored Philly 17-4 through the first six minutes of the quarter.

Offensive balance: Garnett, Bradley, Allen, Paul Pierce and Brandon Bass all took between nine and 12 shots and all five players scored in double figures. Combined, they shot 33-for-54 and scored 85 points, outscoring the Sixers in their time on the floor.

Second half Rondo: Rajon Rondo did not have a very good first half. He took only two shots and his six assists were offset by five turnovers. It was the passive Rondo, as opposed to the locked-in player we’ve seen over the last month. The third quarter was a totally different story. Just after a pass to no one that seemed to indicate more of the same, Rondo took it upon himself to drain fallaway jumpers with the shot clock running down from opposite sides of the court. He had nine assists and zero turnovers in the quarter and the Celtics scored 34 points on one of the best defenses in the league.

WHAT WENT WRONG

Turnovers: The one thing the Celtics said they couldn’t do against Philadelphia was turn the ball over. So, naturally they turned it over five times in the first quarter. That was the only thing that kept Philly in the game because when they weren’t turning it over, the Celtics were shooting 65 percent (11-for-17) in the first quarter.

Foul trouble for the Stiemer: His third foul came on what appeared to be a clean block in the third quarter. His fourth came a few seconds later and his fifth followed shortly after that. After the block, Garnett jumped off the bench to protest the call. Rondo raced over to referee Tony Brothers to also voice his displeasure. There’s a method here. The Celtics have two and half weeks to convince the refs that Stiemsma can play defense without fouling. They need him on the court in the playoffs.