For a second consecutive game, the Celtics produced an underwhelming second half. But this time, they weren’t playing the defending champions.

The Celtics, once again, came out sluggish after halftime on Sunday – a theme they must fix in their pursuit of a championship – but they were ultimately too much for the middling Rockets. Kristaps Porzingis was too dominant. The Celtics, unlike Friday’s loss to the Nuggets, were the better team in crunch time as their defense came up big down the stretch. The C’s, in a game they should have been easier, held on for a 116-107 victory.

Porzingis scored 32 points on six 3-pointers in addition to five blocks, Brown had his third career triple-double with 13 points, 11 rebounds and 10 assists, and White contributed 21 points with a career-high 12 rebounds as the Celtics bounced back from Friday’s loss with a victory. They are now 9-1 following losses this season, and have not dropped back-to-back games since Nov. 6 and 8.

The Celtics led by 15 at halftime and had a prime opportunity to bury the shorthanded Rockets – who were without Fred VanVleet – and get some extra rest with a back-to-back looming in Dallas on Monday night. But they came out way too flat in the third quarter. After briefly getting it together to go on an 8-0 run and take a 17-point lead midway through the quarter, the Celtics let their foot off the gas again. As turnovers and missed shots piled up, the Rockets got into transition and made the Celtics pay.

Aaron Holiday’s 3-pointer with 2:25 left in the third cut Boston’s lead to five. The C’s responded and White’s step-back triple restored their lead to 10 entering the fourth, and Payton Pritchard hit a 3-pointer to put the C’s up 11 early in the fourth. The Rockets answered with an 8-0 run, which included five straight points from Dillon Brooks, that suddenly cut the Celtics’ lead to three.

But the Celtics didn’t waver down the stretch. With an effective double-big lineup that included Luke Kornet, the C’s fended off the Rockets’ rally. Still leading by three, Kornet blocked Brooks at the rim, and Joe Mazzulla called timeout. The Celtics then scored five consecutive points – a jumper from Porzingis and a Pritchard triple – sandwiched around another Kornet block that restored control.

The Rockets hung around, trailing by seven with under five minutes to play, but the Celtics continued to hunt mismatches for Porzingis, who scored two buckets in a row. Holiday responded with a 3-pointer, but the Celtics closed it out as Kornet scored a tip-in before Porzingis’ fifth block led to two free throws for Jayson Tatum, who gave them a 12-point lead with 2:01 to go.