Teen Borna Coric beats Denis Istomin in Open 13 first round

Rising teen star Borna Coric of Croatia beat Denis Istomin of Uzbekistan 6-4, 7-5 to reach the second round of the Open 13 tournament on Monday.

Last October, the 18-year-old Coric upset second-seeded Rafael Nadal in straight sets to reach the semifinals of the Swiss Indoors and announce himself as one of the rising stars of tennis.

Although Istomin had more aces -- nine to Coric's three -- he dropped his serve three times compared to once for the Croatian.

Also Monday, Ukraine's Sergiy Stakhovsky downed eighth-seeded Czech player Lukas Rosol 6-3, 6-2 in less than one hour.

The 29-year-old Stakhovsky was in clinical form, serving nine aces and breaking Rosol's serve twice in each set, while not facing a single break point on his serve in the match.