ST. PETERSBURG, Russia (AP) Fifth-seeded Alexander Zverev reached the second round of the St. Petersburg Open with a straight-sets win over Russian wildcard Karen Khachanov on the opening day of main-draw play.
The 19-year-old German, ranked 27th in the world, was made to work hard by a fellow youngster for a 7-6 (3), 6-4 win in 1 hour 25 minutes.
Zverev's next opponent will be another Russian, either Alexander Bublik or Daniil Medvedev.
There were a couple of minor upsets as world No. 62 Adrian Mannarino of France lost 7-6 (7), 3-6, 6-3 to 83rd-ranked Ricardas Berankis, while world No. 63 Diego Schwartzman of Argentina was beaten 6-4, 6-4 by Czech Lukas Rosol.
The hard-court tournament has a $923,000 prize fund.