ST. PETERSBURG, Russia (AP) Third-seeded Dominic Thiem breezed into the quarterfinals of the St. Petersburg Open on Wednesday, beating his fellow Austrian Andreas Haider-Maurer 6-2, 7-6 (2).
From 2-1 down in the first set, Thiem won the next seven games to take the set and go a break up in the second as Haider-Maurer struggled with his serve.
Errors from Thiem helped Haider-Maurer to level the score at 4-4 in the second set, but Thiem cruised to victory in the tiebreak.
The 22-year-old Thiem is chasing his fourth ATP title of a breakthrough season.
Eighth-seeded Mikhail Kukushkin of Kazakshtan went out in the first round, beaten 7-6 (4), 2-6, 6-2 by Uzbekistan's Denis Istomin.