HOUSTON -- James Harden wore a somber expression in a virtually empty locker room late Thursday night, a scene that painted the perfect picture of the Houston Rockets' season-long struggle with failure and frustration.

Phoenix's P.J. Tucker and Mirza Teletovic shared the offensive load, and the Suns dealt a severe blow to the Rockets' fading postseason hopes with a 124-115, comeback victory at Toyota Center.

The Suns (21-58) snapped a seven-game slide by immediately answering the Rockets' 7-0 spurt with a 12-0 run of their own in the fourth quarter.

Houston (38-41) had surged to a 110-107 lead, but starting with two Devin Booker free throws with 3:10 left, Phoenix wrested control and did severe damage to the Rockets' playoff designs.

The Rockets, with three games remaining, trail the Dallas Mavericks by 2 1/2 games and the Utah Jazz by 1 1/2 games.

"(It's) extremely tough (to) come back home after a tough loss (in Dallas on Wednesday) and just give the game away," Harden said. "We've still got an opportunity, we've just got to win out and have some other teams lose."

Tucker tallied 24 points and 12 rebounds, and Teletovic added 26 points off the bench. Tyson Chandler scored 21 points and grabbed 10 boards, and it was his dunk with 25 seconds left that capped the decisive run.

The Suns bludgeoned Houston on the boards, turning 20 offensive rebounds into 36 second-chance points and a plus-20 edge in shot attempts. Even with nothing to play for beyond professional pride, the Suns outworked the Rockets, rallying twice from double-digit deficits.

"It's the hardest thing in the world," Tucker said of staging a comeback without incentive. "That's why you're a pro. Me, Ronnie (Price) and Tyson try to teach these guys if you get down, the NBA is a long game. It's a game of runs. You've got to keep playing, keep fighting, keep chipping away."

Harden missed just four of 14 shots and paced Houston with 30 points. He also dished out seven assists. Trevor Ariza chipped in 22 points on 8-of-11 shooting. The Rockets lost for the seventh time in 10 games.

Teletovic scored 11 points in the second quarter to key the rally from a 41-29 deficit. He followed a 23-foot jumper with a layup to pull Phoenix to within 45-41 before later hitting a 3-pointer that shaved the margin to 48-47.

With 17 first-half points, Teletovic almost singlehandedly kept the Suns in contention. When Houston scored the opening 10 points of the third quarter, Tucker caught fire and picked up where Teletovic left off.

Harden capped a Houston run with a 3-pointer, but 25 seconds later, Tucker completed a three-point play to initiate the comeback. Tucker added a reverse layup out of the post, a 7-foot jumper, and a 3-pointer before his reverse layup cut the deficit to 77-69.

"He's our X-factor," Suns interim coach Earl Watson said of Tucker. "He's always been a vocal leader, he and Tyson Chandler. Anytime you have vets still playing the way they're playing and they're not looking forward to the summer, everyone else has to fall in line, and it sets the tone for the rest of our young guys."

Teletovic, who re-entered the game as a substitute for Chandler with 6:21 left in the third, followed with a 3-pointer and a difficult bank shot from the post. When Archie Goodwin (16 points off the bench) completed a three-point play, the Suns led 82-81.

Despite shooting a season-high 56.8 percent, the Rockets faltered once Phoenix applied late pressure. This collapse resembled so many others.

"I think there's a sense of frustration that set in a little bit down the stretch," Rockets interim coach J.B. Bickerstaff said. "I won't say those guys weren't trying. I won't say that. It matters to those guys; it bothers those guys. It stings to all of us."

NOTES: Suns interim coach Earl Watson lauded the contributions of F/C Alan Williams, who signed a multiyear contract with Phoenix on March 18 after his initial 10-day contract expired. Williams averaged just 1.7 points and 1.8 rebounds in his first six games, but his energy and enthusiasm left Watson raving. ... Given their desperation relative to the postseason picture, the Rockets are in no position to scale back the minutes of G James Harden, who was averaging 42.6 minutes in his last eight games before playing 43 minutes Thursday. He leads the NBA in minutes (3,021) and minutes per game (38.2). ... Suns F Jon Leuer returned to action after missing two games with a right ankle sprain. He scored four points in 10 minutes.