Parker had 22 points and 10 assists in his return from a four-game absence, and San Antonio never trailed in a 108-101 victory over the Sacramento Kings on Friday, a day the Spurs lost two key players.
San Antonio (58-21) clinched at least the No. 2 seed in the Western Conference following Denver's 108-105 overtime loss Friday in Dallas.
The good news didn't resonate in the locker room, where the Spurs were still dealing with the decision to waive forward Stephen Jackson on Friday afternoon, ending his second stint with the team.
Hours earlier, San Antonio also lost reserve forward Boris Diaw, who will miss three to four weeks after having surgery Friday to have a synovial cyst removed from his lumbar spine.
Jackson's departure took the team by surprise, especially since the playoffs start in eight days.
"It's a hard one," Parker said, "but it's a big-boss decision."
"We probably look a little thin, but life goes on," Spurs coach Gregg Popovich said before the game. "Nobody knew it was going to be two or three weeks for Boris, but the two events are basically mutually exclusive in the sense of what had to be done."
The Spurs needed everyone to step up in the wake of a depleted roster, and they did so.
The Spurs shot 54 percent from the field overall (42 for 77) and were 4 for 8 on 3-pointers in the second half.
"When we run our offense, this is what happens," Leonard said. "A lot of guys get open shots and they knock them down."
Leonard sparked an 11-2 run, continually beating John Salmons to the basket for a pair of layups, a dunk and a free throw that gave San Antonio a 15-6 lead. He played 35 minutes with his primary backup, Jackson, no longer with the team.
"That's Kawhi's position and he plays a lot of minutes," Popovich said. "That's what we want him to do. We want him to play 35-40 minutes a game. He's a heck of a player and he needs minutes, so he's going to get them."
Sacramento shot 4 for 22 to start the game, missing seven straight early in the quarter. San Antonio held a 23-13 lead after the first, the second-lowest point total by a Spurs opponent in the opening quarter this season.
"Sometimes when you don't make shots you don't have that backup to say, `OK, next time we get it and get a lot of defense going," Kings coach Keith Smart said. "When young teams and veteran teams miss a couple of shots right away, they drop their shoulders."
Parker didn't attempt a shot in the first quarter, but still led the team with 13 points in the first half.
His first points came on a layup with 3:38 left in the second quarter, and closed the first half by scoring 13 of the team's final 15 points.
"He started to take over the game in the second quarter," Leonard said. "It was fun watching him get us the lead."
Sacramento opened the third quarter on 15-6 run to pull within 66-65 with 5:49 left in the quarter, but San Antonio quickly rebuilt a 10-point lead on a pair of buckets apiece from Leonard and Parker.
The Spurs were outscored 27-24 in the fourth, but their lead was never really threatened to end the tumultuous day.
"(Reaction) starts at the top," said Spurs guard Gary Neal, who had 10 points. "Timmy shows up and does his job. Tony shows up and does his job. There's not a lot of gossiping about the situation. It is what it is and we try to prepare ourselves to win games."
Duncan was averaging 22 points, 10.6 rebounds, 2.73 blocks and 2.7 assists in his 11 games prior to Friday's victory. . Cousins picked up his league-leading 15th technical foul with 2:22 left in the first half after he was whistled for pushing Duncan. Cousins was upset there was no foul called on Duncan on a steal.
The Phoenix Suns selected Croatian forward Dragan Bender with the No. 4 overall pick of the 2016 NBA draft on Thursday night.
With the second pick in the NBA draft, the Lakers take Brandon Ingram.
The Boston Celtics selected California forward Jaylen Brown with the No. 3 overall pick of the 2016 NBA draft on Thursday night.