HOUSTON -- With another back-to-back looming, the last thing the Houston Rockets wanted was to extend maximum effort deep into the second half against an inferior opponent. Their bench occupants in the fourth quarter revealed a job well done.

Guard James Harden posted his 24th double-double, and Houston turned a breakout first quarter into an easy 131-115 win over the Phoenix Suns on Monday night at Toyota Center.

The Rockets (23-9) recorded their second victory over the Suns (9-22) in less than a week by establishing an early advantage and not squandering it as they did last week in Phoenix, when Houston didn't pull away for good until the fourth quarter. The Rockets scored 39 points in the opening period Monday and led by as many as 34 points in the second half, draining 15 3-pointers en route to the victory.

"I thought the first quarter, the first half was really good," Rockets coach Mike D'Antoni said. "The third and fourth we just tried to outscore them. That's normal. It's human nature."

Harden finished with 32 points and 12 assists, his ninth 30-point, 10-assist game this season. Forward Ryan Anderson added 15 points, including 10 in the runaway first, while forward Trevor Ariza posted eight points, 10 rebounds and five steals. Four other Rockets scored in double figures to fuel the rout.

While winning 10 consecutive games to open the month, the Rockets were ranked second in the league in defensive efficiency. That ranking dropped to 23rd while losing two of three games last week, so besides ending things early with the Dallas Mavericks on deck Tuesday, Houston aimed to focus on defense.

"When we put effort and energy into both sides of the ball, we can be a really good team," Ariza said. "It showed tonight, and we've just got to continue to do those things."

Phoenix, 26th in defensive rating entering Monday, allowed the Rockets to shoot 50 percent.

Eric Bledsoe paced the Suns with 24 points, while his backcourt mate Devin Booker chipped in 16 points. That tandem combined for eight rebounds, eight assists and four steals but shot just 14 of 38 from the floor, including 2 of 13 from behind the 3-point arc.

Brandon Knight scored 21 points off the Phoenix bench. Rookie Dragan Bender had his first career double-double with 11 points and 13 rebounds plus three steals for the Suns, who have dropped five of six games.

"It's tough when you're giving up everything. Threes, layups, and it's really tough," Bledsoe said. "They had 20-something points in the first half on transition points, so I don't think we were really guarding anybody."

Behind back-to-back 3-pointers from Anderson and guard Patrick Beverley, who departed in the second half with a thigh bruise and is questionable for Tuesday, the Rockets dashed to a 10-2 lead.

The Suns closed within two points midway through the first quarter before the Rockets started to pull away while limiting Phoenix to a pair of field goals over a three-minute stretch during their 14-4 run.

Trailing 51-27 following a 3-pointer from Houston reserve forward Corey Brewer, the Suns fashioned one last surge into contention, cobbling together a 14-4 run that sliced the deficit to 14 and forced a Rockets timeout. Houston responded by allowing Phoenix just one basket the remainder of the first half, with Harden converting an elbow jumper, two free throws and a layup to ignite a 14-2 run for a 69-43 lead.

Harden sank a 3-pointer with 7:56 left in the third quarter to push the Rockets' lead to 88-54. From there it was easy sledding as Harden played a team-high 30 minutes and watched the fourth from the bench.

"They did a great job of attacking the paint and finishing at the rim," Suns coach Earl Watson said of the Rockets. "We did a better job in the third quarter in coming out fighting, playing."

NOTES: Rockets coach Mike D'Antoni announced that C Clint Capela will return at some point in January. Capela missed his fourth consecutive game on Monday with a small left fibula fracture incurred at Minnesota on Dec. 17. ... With Capela sidelined D'Antoni has moved away from holding out veteran C Nene in back-to-backs, a practice he adhered to before Capela was lost. Nene played in both games of a back-to-back last week against the Spurs and Suns. The Rockets will play at Dallas on Tuesday night. ... Suns coach Earl Watson spoke to his insistence that the Oklahoma City Thunder draft James Harden in 2009 when Watson played for the team. Watson, who played collegiately at UCLA, was intimately familiar with Harden, who grew up in Los Angeles.