DETROIT -- Reggie Bullock started just seven games in his first four NBA seasons. Bullock became a regular member of the Detroit Pistons' lineup earlier this month and he's doing everything possible to retain that status.

His confidence continues to grow and he played arguably his best game this season on Saturday, lifting the depleted Pistons to an unlikely victory.

Bullock had a career-high 22 points and played an instrumental defensive role in Detroit's 93-79 win over the San Antonio Spurs at Little Caesars Arena.

Bullock is averaging 13.6 points in the last eight games. The Pistons are 9-3 in games he has started.

"This is probably the freest I've played since I've played in the league," said Bullock, a 6-foot-7 swingman. "Just knowing coach (Stan Van Gundy) believes in me, my teammates believe in me and just believing in my skill to defend, run the lane, rebound, shoot 3s. So I'm just trying to do it all to help my team with players down and it's working out for me."

Bullock, who was 9 of 14 from the field, had never scored more than 20 points in his five-year career. Rookie guard Luke Kennard also established a career best with 20 points. Kennard's previous best was 14 points.

"Luke played really, really well and it helped that he made shots because he and Bullock were the only ones who could make threes," Van Gundy said.

The Pistons knocked off one of the elite Western Conference teams without three of their top players. Detroit shooting guard Avery Bradley was sidelined for the seventh consecutive game with a groin injury. Point guard Reggie Jackson is out until after the All-Star break with a severe ankle sprain. One of the team's top reserves, Stanley Johnson, sat out due to a hip strain.

"It all stemmed from the defensive effort," Van Gundy said. "That's where everything came from. I just thought we played extremely hard. If you put that much effort into the game, you can live with the results one way or another."

Andre Drummond supplied 14 points, 21 rebounds and six assists for the Pistons (20-15). Ish Smith contributed 18 points and four assists, and Tobias Harris added 12 points, six rebounds, and five assists.

Kawhi Leonard led the Spurs (25-12), who had their three-game winning streak snapped, with 18 points. But Leonard did most of his damage at the foul line, as he went 4 of 11 from the field while being hounded by Bullock.

"They were significantly undermanned and they were physical," Spurs coach Gregg Popovich said. "They executed really well. Stan had them prepared mentally. We tried to battled back, got back in it here and there, but kept making the same mistakes."

LaMarcus Aldridge had 15 points and 11 rebounds and Bryn Forbes tossed in 10 points for San Antonio, which scored a season low in points. Its previous low was 86 against Minnesota on Nov. 15.

Bullock's corner 3-pointer midway through the third gave Detroit a double-digit advantage at 57-47. San Antonio gradually chipped away and got within six at 63-57 entering the fourth quarter.

Kennard's 3-pointer from the right wing with 10:26 left nudged the Pistons' advantage to 70-61. He established his career best with a lane jumper to make it 74-63. Bullock's fast-break layup after a Drummond steal increased the lead to 78-63. Harris then finished off the run of eight straight points with a dunk off a Drummond feed.

Bullock notched his career high with a corner 3-pointer for an 88-69 lead.

"It was a bad combination of executing poorly on defense when we got back in the game and not making a shot," Popovich said. "I think we shot 20 percent from three and in the 30s overall. It's tough to win on the road like that."

NOTES: Pistons coach Stan Van Gundy said 7-foot-3 center Boban Marjanovic has gotten limited playing time because of his lack of mobility. "You're dealing with a lot of guys that can really stretch the floor," Van Gundy said. "You've got to be able to defend 25 feet out on the floor, so it's a difficult thing." ... Spurs SF Rudy Gay missed the game with a right heel injury. He'll be out at least two weeks. ... San Antonio tied its season low for a quarter with 13 first-quarter points. ... Pistons C Andre Drummond has 25 of the team's 27 double-doubles. ... San Antonio has a 19-1 record when it scores 100 or more points.