PHOENIX -- Bryn Forbes knew he hadn't made a 3-point shot all night. But that didn't stop him from thinking the next one was going in.

And it was the one the San Antonio Spurs needed the most.

A watered-down Spurs lineup needed Forbes' big shot with 21.5 seconds left to hold off a furious Phoenix Suns rally and secure a 104-101 win on Saturday night.

Forbes was 0 of 5 from 3-point range and 4 of 12 from the field before his winning shot, but he was more than ready to take it.

"We drew up the play and I knew I was probably going to shoot it. I think every shot is going in whether I miss five, six or 10,” said Forbes, who made his second start of the year and played 36 minutes. "The (Suns) made some tough plays and fought back, but our vets led us to the win."

LaMarcus Aldridge had 20 points and nine rebounds for the Spurs (19-8). Patty Mills added 20 points and set up Forbes' winning shot to give San Antonio its fourth straight win and its eighth in the last nine games despite missing a host of players, including injured Danny Green, Kawhi Leonard and Tony Parker.

Pau Gasol and Manu Ginobili, who played key roles in the home win against the Boston Celtics on Friday, stayed home to rest.

"A lot of these guys haven't been in that type of moment in a game," Aldridge said. "We had some mistakes, but having them get better and used to this is only going to make us better."

Down 19 points in the third quarter, the Suns got back in it with a 26-9 run and took their first lead at 100-99 on a Marquese Chriss runaway slam with 1:19 left in the game.

But after Josh Jackson made one of two free throws to extend the Phoenix lead to two, Mills found Forbes coming off an Aldridge screen in front of the Spurs' bench to give San Antonio the lead for good.

"He's never seen a shot that he didn't like and that's a good quality when you can shoot the ball well," Spurs coach Gregg Popovich said. "We're thrilled. It was our fifth game in seven nights and a back-to-back on the road. They were pretty tired but hung in as well as they could.”

Mike James had 25 points off the bench and TJ Warren had 19 of his 24 points in the second half for the Suns (9-19), who have lost eight of the last 10 and two straight since losing star Devin Booker to an adductor strain. But they didn’t go down easily in the stretch run.

“We had to play with some heart. They were embarrassing us a little bit, especially coming off a back-to-back and resting players,” said Chriss, who had 15 points and eight rebounds. “That's a slap in the face sometimes, so you try to take it personal."

The Spurs led by as many as 14 in the first quarter. Davis Bertans, who didn't play at all against the Celtics, had eight points in five-plus minutes and fed Joffrey Lauvergne for a jumper with two seconds left to give San Antonio a 28-17 lead.

Phoenix missed 13 of 19 shots in the quarter and got only four points from its five starters.

“It took us 24 minutes to find a group that would play with the right energy," Phoenix interim coach Jay Triano said. "I was mixing guys in and out looking for anything that would give us some juice. We finally got it in the second half.”

Down 52-39 at the half and 62-43 in the third quarter, the Suns roared back. Warren had 10 points during the 26-9 run and a Troy Daniels 3-pointer with 52.3 second left cut the deficit to two at 71-69.

NOTES: Suns C Tyson Chandler, who didn't play in three of the past five games, started on Saturday. ... Still without G Tony Parker (injury management) and F Kawhi Leonard (quadriceps) among others, the Spurs played without G Danny Green (groin), and left C Pau Gasol (rest) and G Manu Ginobili home to rest. "The guys have been wonderful pulling together and playing together," Spurs coach Gregg Popovich said of his deep and productive bench. "A lot of people have stepped up you wouldn't have figured to play this many minutes." ... Suns G Devin Booker was shooting free throws Saturday as rehab from his adductor strain took its first baby steps. ... Popovich on the 40-year-old Ginobili's 3-pointer with five seconds left to beat the Boston Celtics Friday. "I didn't plan that. I didn't draw that play. Manu just drew it up in his head like he does."