HOUSTON -- The Houston Rockets spent two months speaking of cohesion and self-discovery, broaching that topic so frequently that when guard James Harden revisited it again Friday night it felt so familiar. Given the Rockets' performance, it was timelier than ever.

Harden drilled consecutive 3-pointers in the fourth quarter to complement a determined defensive effort as the Rockets defeated the Spurs 88-84 at Toyota Center.

Harden shot just 7 for 21 and missed his first three attempts from behind the arc before nailing back-to-back treys to push the Rockets (16-15) to an 84-75 lead with 3:36 left to play. Harden finished with 20 points and nine assists, but it was the Rockets' defense that resonated.

"We were consistent with our defensive effort," Harden said after the Rockets held the Spurs to 40.9 percent shooting. "It was every possession. We had to lock in, and for the most part we did a really good job.

"We're more than capable so we've got to find ourselves. We've got to find that energy, that consistent defensive togetherness every single night."

With the Spurs (25-6) matching the Rockets' defensive might, Harden needed help carrying Houston to the finish line. Center Dwight Howard chipped in 11 points, 12 rebounds and two steals. Forward Terrence Jones was an early force and totaled 14 points and six rebounds.

Veteran guard Jason Terry provided a two-way punch in the fourth quarter, scoring nine of his 12 points off the bench in the final period while adding three steals. Terry did not miss a shot from the floor.

"His energy is infectious," Rockets interim coach J.B. Bickerstaff said of Terry. "His weakside defense when he's running around, scrambling and chasing the ball and rotating on the weakside, the other guys see him doing that and that picks them up (and that) gives them the boost."

Forwards Kawhi Leonard and LaMarcus Aldridge combined for 38 points and 16 rebounds for the Spurs, with Leonard added five steals, four assists and three blocks to his sparkling ledger. Center Tim Duncan produced 13 points and 11 rebounds, but after the teams changed leads 10 times and shared the lead nine additional times through three periods of action, the Rockets led throughout in the fourth quarter.

"I thought they were very physical and aggressive and we didn't adjust to it," Spurs coach Gregg Popovich said. "I thought their pressure hurt us on most situations all night."

The Spurs tapped into their defensive vigor midway through the second quarter to erase what was once a seven-point Rockets lead.

When Houston forward Donatas Motiejunas banked in an eight-footer with 5:37 left in the second quarter, the Rockets led 36-32. But that basket represented the Rockets' last of the half, with Leonard scoring six consecutive points to pull the Spurs even at 38-38 as San Antonio tallied the final seven points of the first half to lead 43-38 at the intermission.

Harden, limited to 1-for-6 shooting and just two points in the first half, came alive in the third quarter. Just over three minutes into the period he produced six points on successive baskets, and his assist on a hook shot from Rockets forward Clint Capela capped a 13-4 run that lifted Houston back in front 51-49. Momentum swung back and forth through the remainder of the period, with guard Ty Lawson giving Houston a 61-60 lead entering the fourth on a pull-up jumper with 46.4 seconds left.

"I just don't think we were as sharp tonight," Aldridge said. "We had some mistakes down the stretch. It was just one of those nights for us."

NOTES: On the heels of a decent performance from G Ty Lawson (11 points and three assists) on Wednesday night at Orlando, Rockets interim coach J.B. Bickerstaff addressed questions concerning a potential change in his starting lineup. Houston is 10-5 with G Patrick Beverley in the starting lineup, and Bickerstaff confirmed that Beverley would remain a starter in the foreseeable future. ... Spurs F Kyle Anderson matched his season high of 10 points on Wednesday at Minnesota and seemingly solidified his role as a viable member of the rotation with a season-high 12.9 game score. ... Friday marked the ninth time the Rockets played on Christmas but the first time they have done so in Houston since the franchise moved from San Diego.