Two weeks of NBA Summer League play in three different cities has been enough for teams to hold out many marquee players late this week, though there was plenty of intensity on the floor Saturday in the quarterfinal round of tournament play in Las Vegas.
The losers go home instead of the semifinal round Sunday.
Wayne Selden scored 24 points and led the Memphis Grizzlies to a 98-95 double-overtime victory over the Miami Heat.
"It was a real sloppy game on our part," Selden told the ESPN broadcast. "But down the stretch we got back to what we do and that's guard and play defense. It was an ugly game, but we made it happen.
"We've got to get the ball moving."
Gian Clavell, who finished with 20 points, hit a 3-pointer with 5.1 seconds left in regulation to force overtime, but the Heat would manage just five total points in the two extra periods.
Selden hit a pair of free throws to force the second overtime and Wade Baldwin hit two more after rebounding his own missed free throw to go up 97-94 with 16.6 seconds left. Clavell missed a 3-pointer to tie just before the final buzzer.
The No. 4-seeded Grizzlies (5-0) will face the No. 16 Portland Trail Blazers on Sunday.
Dillon Brooks, the second-round pick from Oregon, scored 14 and had four steals for Memphis, and 2016 first-rounder Baldwin had 12 points on 4-for-17 shooting.
Miami guard Matt Williams scored 18 and knocked down six 3-pointers.
The Heat held out No. 14 overall pick Bam Adebayo.