Tatum, Celtics 3-0; Summer League set for tournament stage

Jayson Tatum #11 of the Boston Celtics stands on the court during a 2017 Summer League game against the Portland Trail Blazers at the Thomas & Mack Center on July 9, 2017 in Las Vegas, Nevada. Boston won 70-64. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. Ethan Miller/Getty Images/AFP

Jayson Tatum might not need long to win his first championship with the Boston Celtics.

The Celtics improved to 3-0 in the NBA Summer League on Tuesday with an 88-83 victory over the Philadelphia 76ers. Tatum, the No. 3 pick in the draft, had 15 points and six rebounds.

Boston, winner of a record 17 NBA championships, is one of six undefeated teams after the preliminary stage on the campus of UNLV.

The Memphis Grizzlies also are 3-0 after overcoming 37 points from Utah rookie Donovan Mitchell in an 84-81 overtime victory. Mitchell, the No. 13 pick from Louisville, added eight steals.

Toronto is the No. 1 seed, followed by Cleveland, Dallas, Memphis, the Clippers and Boston, as the tournament stage begins. The top eight seeds have byes until Thursday’s second round, while Nos. 9-24 are scheduled to play Wednesday.

A look at the six games played Tuesday, including one that went to sudden death:

CELTICS 88, 76ERS 83

Jabari Bird also had 15 points for the Celtics, going 7 of 10 from the field. Demetrius Jackson scored all of his 14 in the fourth quarter, while Ante Zizic had 12 points and 13 rebounds.

Jaylen Brown played just 13 minutes, scoring seven points before leaving with a bruised thigh.

Timothe Luwawu-Cabarrot had 16 points for the 76ers (1-2).

GRIZZLIES 84, JAZZ 81, OT

Dillon Brooks came off the Memphis bench for 24 points on 9-of-11 shooting, including a 3-pointer with a minute left in OT. The former Oregon star finished the game by blocking Mitchell’s tying 3-point attempt with 0.2 seconds to play.

Wayne Selden added 17 points and Wade Baldwin IV had 15.

Mitchell scored 14 points in the fourth quarter before Travis Leslie tied it with a jumper with 2.6 seconds to go in regulation. Utah fell to 0-3.

TIMBERWOLVES 78, WARRIORS 76, 2 OT

C.J. Williams made a floater in the lane in the sudden-death second overtime to give Minnesota its second straight victory.

Matt Costello had 14 points and 15 rebounds, while Williams also scored 14 points for the Timberwolves (2-1). Perry Ellis and Marcus Paige each had 13.

Patrick McCaw scored 20 points and Bryce Alford had 16 for the Warriors (0-3), while Jordan Bell provided the defense. The second-rounder from Oregon finished with 11 rebounds, six blocks, five assists and five steals.

SPURS 99, TRAIL BLAZERS 85

Bryn Forbes scored 35 points, making six 3-pointers, as the Spurs improved to 2-1.

Caleb Swanigan, the No. 26 pick out of Purdue, led Portland (1-2) with 19 points and 13 rebounds.

BULLS 82, WIZARDS 73

Lauri Markkanen bounced back from a poor performance with 20 points and 10 rebounds to lead the Bulls over the winless Wizards.

Markkanen, the No. 7 pick from Arizona, missed all 10 3-point attempts and went 1 for 13 overall in a loss a night earlier.

Antonio Blakeney led Chicago (1-2) with 23 points while Denzel Valentine, who also struggled Monday, contributed 15 points and six rebounds.

Sheldon McClellan scored 20 points for Washington (0-3).

MAVERICKS 78, HEAT 73

Yogi Ferrell, a second-team All-Rookie selection, scored 23 points to lead the Mavericks in the battle of unbeatens.

No. 9 pick Dennis Smith Jr. added 16 points and five assists as Dallas improved to 3-0.

Okaro White had 17 points and 11 rebounds, while rookie big man Bam Adebayo had 13 points and nine boards for Miami (2-1).