Sixth-seeded Marcel Granollers defeated Mischa Zverev 6-4, 6-2 Tuesday to reach the second round of the Gerry Weber Open.

The 26-year-old Granollers overcame resistance from the Russian-born Zverev, who is ranked 190th.

Zverev held his serve and saved six break points before Granollers finally broke him in the ninth game to take a 5-4 lead to take the first set. The 22nd-ranked Spaniard broke the German twice in the second to wrap up the match.

Granollers will play veteran Tommy Haas, who advanced after Bernard Tomic retired after 22 minutes while trailing 5-2. Haas said Tomic had told him he'd been ill.

Also, Radek Stepanek edged seventh-seeded Andreas Seppi 7-6 (6), 4-6, 7-6 (7).

Viktor Troicki stopped Benjamin Becker 6-2, 7-6 (6) to set up a second round meeting with third-seeded Tomas Berdych.

Earlier, Florian Mayer beat American qualifier Tim Smyczek in straight sets to set up a second round meeting with five-time winner Roger Federer on Wednesday.

The same day, Rafael Nadal will open against Lukas Lacko, who beat Konstantin Kravchuk 2-6, 6-2, 6-3 in the first round.

Nadal won a record seventh French Open championship on Monday after defeating top-ranked Novak Djokovic at Rolland Garros.