American Sam Querrey rallied from down a set to beat Ivo Karlovic of Croatia 4-6, 7-6 (4), 6-4 and reach the second round of the Moselle Open on Monday.
The 31st-ranked American, who is seeded sixth in Metz, got off to a slow start but managed to force a tiebreaker in the second set and pull through in the only first-round match of the day.
The match featured 37 aces, including 25 from the 34-year-old Karlovic.
Querrey comes into the tournament after a disappointing second-round exit at the U.S. Open.
Defending champion Jo-Wilfried Tsonga is seeded No. 1 and has a bye into the second round.