Donovan Mitchell scored 23 in his pro debut and Dante Exum added 18 as the Utah Jazz beat the San Antonio Spurs 87-74 in Utah Summer League Action.brFor more information, as well as all the latest NBA news and highlights, log onto the leagues official website at Subscribe to NBA LEAGUE .brBryn Forbes scored 31 points and Davis Bertans added 14 as the San Antonio Spurs defeated the Boston Celtics 81-70 in Utah Summer League action. Jayson .brDante Exum capped a strong Summer League showing with 16 points to lead the Utah Jazz to a 68-65 win over the Boston Celtics and a 3-0 record in Utah .