It was the third consecutive home loss for Boston, which remained in the fourth spot in the Eastern Conference playoff race.Aaron Brooks scored 30 with nine assists for Houston, hitting a 3-pointer with nine seconds left in regulation to send the game into overtime. Chase Budinger added 24 points for the Rockets.
Paul Pierce scored 27 points and Rajon Rondo had 23 for Boston. Rondo added 10 assists to surpass Hall of Famer Bob Cousy for the Celtics' single-season franchise record.
Rondo also had five steals and five rebounds. He has 724 assists for the season, topping Cousy's total of 715 in 1959-60.
Boston scored 11 consecutive points in the fourth quarter to turn a 91-87 deficit into a seven-point lead. But the Rockets came back, finally tying it with 1:15 left on Kyle Lowry's falling-down drive that made it 104 all.
Kevin Garnett hit a pair of free throws with 60 seconds left to give Boston a 106-104 lead, and the Rockets resorted to fouling to keep it close. The Celtics missed three free throws in the last 48 seconds, allowing Houston to tie it on Brooks' 3-pointer.
Pierce dribbled down to the final second for Boston before putting up an off-balance jumper at the regulation buzzer that wasn't close.
In overtime, the Celtics opened a 114-109 lead when Rondo scored on a fast break with 3:20 left. But they did not score again.
Budinger pick up a loose ball and hit a 3-pointer to make it a one-point game with two minutes left. After Tony Allen's miss, Scola scored on a putback to give the Rockets the lead.
Scola added a long 2-pointer with 52 seconds left to make it 117-114 and, after Kendrick Perkins was called for a moving pick, Brooks made a pair of free throws to clinch it.
Rondo picked up a pair of assists early in the first, the second to set up Garnett with 8:45 left in the quarter and surpass Cousy. At the next break, the milestone was noted over the public address system, and the fans and Rondo's teammates applauded.
Cousy retired in 1970 as the NBA's career leader with 6,955 assists. He is 14th now.
The Celtics led by 11 points midway through the first quarter, but the Rockets scored 16 of the next 19 points — and 10 in a row — to turn a double-digit deficit into a 29-27 lead with 60 seconds left. Houston led by as many as seven points in the second and took a 57-53 halftime lead when Budinger hit a 3-pointer with four seconds left.
Notes
Ray Allen scored five points and played just 16 minutes because of foul trouble. … The 119 points were the most allowed by the Celtics this season. … Trevor Ariza missed the game with flu-like symptoms.