OKLAHOMA CITY (AP) — Oklahoma City didn't have star Shai Gilgeous-Alexander against San Antoni. Jalen Williams' spot-on imitation was good enough.
Williams scored a season-high 27 points and the Thunder overcame a 20-point second-half deficit to hand the Spurs their ninth straight loss, 119-111 on Wednesday night.
Gilgeous-Alexander, the league's No. 3 scorer with 31.1 points per game, sat out with a bruised hip. Williams stepped up, scoring 20 points on 8-for-8 shooting in the second half.
"He was big-time," Thunder coach Mark Daigneault said. "He was really good. Continues to get better."
Williams even hit a clutch jumper like Alexander often does. With the Thunder up 113-111, Williams' short pullup jumper bumped the lead to four with 30.8 seconds to play and put Oklahoma City in control for good. The 6-foot-6 guard made 11 of 15 shots overall and had six rebounds.
Daigneault said Williams has great potential.
"He strong, he's tough, he's smart and he's got great length and size," Daigneault said. "Once his fundamentals catch up to the rest of those ingredients, he's going to be a really great defensive player, too."
Lu Dort scored 23 points and Josh Giddey added 14 points and 14 rebounds for the Thunder.
Devin Vassell scored 25 points and Keldon Johnson added 19 for the Spurs, who shot 28% in the second half.
"The purpose we had in the first half - it just dissipated in the second half," San Antonio coach Gregg Popovich said.
San Antonio led 77-60 at halftime after shooting 64% from the field. Vassell scored 16 points before the break and Johnson added 13. The Spurs led 96-88 heading into the fourth.
A steal and layup by Tre Mann tied the game at 98 early in the fourth quarter, and the game was tight from there.
Daigneault said the Thunder came out with the right approach in the second half.
"We just had way more of a care factor, and we were way tougher," he said. "We shut the paint off, shut the glass off, contested everything. We were not as tough as we aspire to be at all in the first half."
San Antonio shot just 30.4% in the fourth quarter.
"Forty-eight minutes is a long time," Popovich said. "We've had a lot of good halves or 2 1/2 quarters and all that, but rarely have we put four quarters of fundamental, sound defense and basketball together. Part of it's a young team. But they're a young team too, and they did it. They deserve credit."
It was the second time this season the Thunder played without Gilgeous-Alexander. The first time, Oklahoma City lost to the Minnesota Timberwolves 116-106 in the third game of the season.
Dort had one of his best offensive games of the season.
Oklahoma City's No. 3 scorer for the season made 7 of 15 field goals against San Antonio, including 3 of 7 3-pointers. He fell one point of his season high, which he had reached twice.
Spurs: F Isaiah Roby, who started 62 games for the Thunder the previous two years, was cheered when he entered the game. He finished with four points and five rebounds in 17 minutes. ... G Josh Richardson missed his fourth straight game with a sprained right ankle. ... F Doug McDermott left the game in the second half with ankle soreness.
Thunder: F/C Mike Muscala sat out with a fractured left pinky finger. ... Made 12 of 23 field goals in the third quarter to get back into the game. ... Mann scored 16 points.
Spurs: Host New Orleans on Friday night.
Thunder: At Minnesota on Saturday night.