THE SIDELINES : Chang Gains Volvo Quarterfinals

Michael Chang beat fellow Californian Derrick Rostagno 6-3, 6-2 today to reach the quarterfinals of the Volvo International tennis tournament.

Chang had four aces and never lost more than two points on his serve. He broke Rostagno once in the first set and twice in the second. Rostagno had his best chance to break Chang when he won the first two points in the second game of the second set. But Chang won the next 12 points for a 4-0 lead.

After winning the French Open and turning in a grand showing at Wimbledon, Chang is hoping to improve on his last U.S. Open performance. He won three matches in the 1988 Open before losing in straight sets to Andre Agassi.

With Agassi seeded first and Chang second in this week’s Volvo Tournament, the two American teen-agers are on track for their first tournament meeting since the Open.

Agassi is to play unseeded David Wheaton, a 6-1, 6-4 upset winner over No. 16 Scott Davis, later today.