By Gary Washburn, Globe Staff

LAS VEGAS -- The Celtics improved to 6-1 in summer league and 2-0 in Las Vegas with a 79-74 victory over the Chicago Bulls as Boston took the lead early in the second quarter and never trailed again.

E'Twaun Moore produced his best game of the summer, tallying 25 points on 10-for-19 shooting with 7 rebounds and 2 assists in 33 minutes. Moore won his matchup with Kentucky rookie Marquis Teague, who finished with 8 points on 4-for-17 shooting and six turnovers.

"It's a great sign," Celtics summer league coach Tyronn Lue said about Moore's development. "He's trying to become a point guard but he's a natural scorer. So I just want him to be aggressive and it's a fine line between the two but we know we can score and attack but with Jared (Sullinger) shooting 3 for 15 tonight, he had to step up and score and that's what point guards do."

Although Sullinger continues to struggle from the field -- 24 for 68 (35.2 percent) during the summer league -- he grabbed 14 rebounds in 28 minutes. He grabbed three rebounds in one sequence but missed three putbacks.

Rookie Kris Joseph hyperextended his left knee in the first half and was held out of the second half for precautionary reasons but Lue said the injury is not a concern.

The Celtics are off Wednesday but finish their summer league slate with three more games in Las Vegas -- Thursday against Sacramento (6:30 p.m. ET), Saturday against Milwaukee (10:30 p.m.h ET) and Sunday against the Los Angeles Clippers (6 p.m. ET).