Frenzy became bedlam on the next play. Flagg talked trash to James, ran to his spot on the left wing, pivoted off the catch and nailed the shot before turning to exult with his future Mavericks varsity teammates, who cheered him on decked out in casual wear from their courtside seats.

Cooper Flagg made his NBA Summer League debut Thursday night and although he and the Dallas Mavericks earned the win, the No. 1 NBA Draft pick called it “one of the worst game of my life.”

LAS VEGAS (AP) — Cooper Flagg strolled into UNLV’s Thomas and Mack Center at 4:17 p.m. on Thursday, wearing Dallas Mavericks gear, bright white New Balance shoes, and an emotionless look on his face as he passed through security.