Shai Gilgeous-Alexander scored 28 points, and the Oklahoma City Thunder matched the best 25-game start to an NBA season by dominating the Phoenix Suns 138-89 in an NBA Cup quarterfinal on Wednesday.

The Phoenix Suns trailed by as many as 53 points in suffering their worst loss ever, falling 138-89, to defending NBA champion Oklahoma City in an NBA Cup quarterfinal game Dec. 10 before a sellout cr...