Boston ? After a record-setting seven overtimes in the first six games, the defending NBA champion Boston Celtics made an early night of it with a dominating stretch in the second.

That’s second quarter, not second OT.

Ray Allen followed his 51-point Game 6 performance with 23 on Saturday night, Paul Pierce added 20, and Boston pulled away from Chicago just before the half to finish the Bulls, 109-99 — a rare regulation victory in what might have been be the best first-round playoff series in league history.

“I don’t see great. I just see hard,” said Celtics coach Doc Rivers, whose team will play the Orlando Magic in Game 1 of the Eastern Conference semifinals on Monday. “For a coach, it’s just: Win the series.”

Ben Gordon scored 33, and Kirk Hinrich scored 14 of his 16 in the fourth quarter to help Chicago cut it to three points — thanks in part to a bizarre scoring change that added a point to the Bulls’ score two hours after a first-half three-pointer was mistakenly ruled a two.

Boston made all 11 of its free throws in the last two minutes to hold on, and the seventh-seeded Bulls return to Chicago knowing they took the defending champs to the limit — and quite often beyond. The four overtime games were a record for a series, and the seven overtimes total were the most any team has ever played in an entire playoff — and it’s just the first round.

“It was a long, grueling series. I thought this was one of the most mentally tough series I’ve ever been in,” Pierce said. “Thank goodness we were battle-tested and we were able to pull this out in seven games. … We still are the champs until somebody knocks us off.”

After three consecutive overtime games, the series went from Odyssey to oddity when an unusual scoring correction helped the Bulls cut the deficit to three points in the fourth quarter.

With 5:44 left in the game, the public address announcer said that because of a “technical error” Gordon was credited with a two-pointer instead of a three-pointer, apparently on his basket with 8:32 left in the first quarter. Officials can use video replay to check whether a shot is from beyond the arc or not, but it is supposed to come at the first break after the basket — not three quarters later.