Top-seeded Ivan Ljubicic of Croatia beat Slovakia's Karol Beck 7-6 (5), 3-6, 6-3 on Monday to advance to the second round of the Zagreb Indoors tournament.
Ljubicic, the 2006 champion and a finalist in 2007 and 2008, made the decisive break in the eighth game of the third set. He didn't drop another point after that.
"It was a tough one, but it is important that I won and not how I did it," Ljubicic said, adding that it was his first match for three months.
Fifth-seeded Andreas Seppi from Italy also advanced, after beating Germany's Daniel Brands 6-4, 7-6 (1), while seventh-seeded Robin Haase needed only 57 minutes to record his first victory of the season against Croatian wild card entry Kristijan Mesaros 6-2, 6-3.
Haase won 81 percent of his first serve points against the 23-year-old Mesaros, who was appearing in his first ATP tournament.
Germany's Matthias Bachinger defeated Izak Van Der Merwe of South Africa, 6-3, 6-3, while another Slovak, Lukas Lacko, beat Italy's Potito Starace 7-6 (2), 6-7 (4), 6-3.