This was lockout ugly hoops at its worst. Slow offense, shoddy rebounding, careless turnovers, they were all on display in abundance as the Celtics and Rockets met in a game someone had to win because obviously they both couldn’t lose. The Celtics prevailed, 97-92 because their old men — Paul Pierce and Ray Allen — turned back the clock in the overtime.

It was Allen’s 3-pointer that gave the Celtics a late lead in regulation and Pierce — 30 points, six rebounds — who willed them to the win in the extra session. The old guys still have something left. How much they have for Philadelphia on Wednesday night remains to be seen, but somehow it’s a game for first place in the Atlantic Division.

WHAT WENT RIGHT

The second quarter, for once: Down by seven points after an uninspired first 12 minutes, the Celtics stormed back on the strength of their defense. The Rockets shot 63 percent in the first quarter, but they made only five of 21 shots in the second. The effort started with the much-maligned second unit who managed to score only six points in their four-minute run. However, they also held the Rockets to just two points and Houston started the quarter 1-for-11 from the floor.

Greg Stiemsma had his best game since his last good game: It’s been a long time since the Stiemer had done something of note. You’d have to go all the way back to Jan. 2 when he scored 13 points as a starter to match his production in the first half against the Rockets when he scored eight points on 4-for-6 shooting. Stiemsma was pressed into service after Brandon Bass went back to the locker room to have his ankle re-taped. As with Sunday’s game, Bass’ tape job took over 20 minutes to complete.

Just your average Rajon Rondo: There was very little buzz in the arena and the national television cameras were nowhere in sight. The opponent was Kyle Lowry, an excellent NBA point guard, but not a phenom on par with Jeremy Lin. Rondo was alternately the best player on the court, and the owner of the game’s biggest mistake when he fumbled a ball and missed a breakaway layup that would have iced it. He finished with nine points and 12 assists and outplayed Lowry for three and a half quarters.

WHAT WENT WRONG

Slow starts to halves: The Celtics started the game in a haze, almost as if there was a carryover from Sunday’s emotional overtime win over New York. Rondo was the only active Celtic for most of the quarter and Luis Scola and Chandler Parsons shot 7-for-8 as Houston built a 28-21 lead.

That was only a prelude to a lockout-ugly third quarter in which the Celtics were outscored 28-17 and saw a 10-point lead turn into a five-point deficit. They went without a field goal for the last five minutes, 21 seconds of the quarter.

Not a banner night for KG: Fresh off his string of double-doubles, Kevin Garnett had a rough night against Rockets’ center Sam Dalembert. Not only was he held to just 13 points and seven shots, he also picked up a fourth quarter technical foul and missed two free throws in overtime. Garnett had 13 rebounds, but the Celtics got annihilated on the boards, 57-38.

Bench production lacking: Chris Wilcox was 1-for-4 in an ineffective 20 minutes. Mickael Pietrus missed both his shots and so did Keyon Dooling. The veteran trio scored four points in 44 minutes.