Austria's Andreas Haider-Maurer was the only winner on the opening day of the St. Petersburg Open, beating Daniel Gimeno Traver of Spain in straight sets.
Only one first-round match was played at the event on Monday, which returned to the ATP tour following a one-year absence.
The match was tightly contested, with the two players exchanging early breaks of serve.
Haider-Maurer then saved six break points in the ninth game before earning three set points with Gimeno Traver serving at 5-6, clinching the third to go one set up.
The second set went to a tie-breaker, where Haider-Maurer managed to take the initiative, winning the first five points before going on to seal a 7-5 7-6 (7-2) victory.