Undrafted rookie Ryan Nembhard stole the show while Cooper Flagg showed flashes of star potential in the Mavericks’ Summer League opener. Dallas edged out the Lakers in a thrilling finish—here’s how the young duo made their mark.

Cooper Flagg strolled into UNLV's Thomas and Mack Center at 4:17 p.m. for his Summer League debut, wearing Dallas Mavericks gear, bright white New Balance shoes, and an emotionless look on his face as he passed through security.

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.