Petra Martic clinched her first WTA Tour title by beating Mona Barthel in the Oracle Challenger Series final in Chicago on Sunday.

The Croatian – twice a runner-up in WTA singles finals – was too good for Barthel 6-4 6-1 in the decider.

Martic, the 27-year-old second seed, broke serve five times on her way to victory in one hour and seven minutes at the WTA 125K series tournament.

Barthel served five double faults, beaten in straight sets by Martic for the second time in her career.