LAS VEGAS -- Shai Gilgeous-Alexander scored 20 of his 32 points in the second half, and the Oklahoma City Thunder pulled away late Saturday night to defeat the Houston Rockets 111-96 and advance to the NBA Cup championship.

The Thunder take a five-game winning streak into Tuesday night's final against the Bucks. Milwaukee defeated the Atlanta Hawks 110-102 in the Eastern Conference semifinal. The title game does not count in the league standings.

Saturday night's semifinal pitted two of the top three defenses in the league against each other and both offenses struggled in the first half. However the Thunder, led by Gilgeous-Alexander, found their groove in the second frame, scoring 70 points to pull away after trailing 42-41 at halftime.

Isaiah Hartenstein added 21 points for the Thunder, Jalen Williams scored 20 and Luguentz Dort finished with 19 points and nine rebounds.

Amen Thompson led Houston with 19 points, one of six Rockets in double figures, and Alperen Sengun had 13 points and 11 rebounds.

The Rockets and Thunder have two of the three best records in the Western Conference, making Saturday's second semifinal a potential playoff preview.

The Associated Press contributed to this story.