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.

Rookie Cooper Flagg may not have been happy with his professional debut Thursday night in the NBA Summer League, but he still drew rave reviews all around after the Dallas Mavericks defeated the Los Angeles Lakers,