Seeded players Dominic Thiem, Roberto Bautista Agut and Kei Nishikori all came through their first-round matches at the Gerry Weber Open on Monday.

The third-seeded Thiem hit 19 aces as he defeated Russian qualifier Mikhail Youzhny 7-6 (5), 6-2 for a second-round meeting with Yuichi Sugita. The 52nd-ranked Japanese player defeated German wild card Maximilian Marterer 6-4, 5-7, 6-3.

The fourth-seeded Bautista Agut had little difficulty in beating Jan-Lennard Struff 6-4, 6-1, and the seventh-seeded Nishikori opened his grass-court campaign by beating qualifier Matthias Bachinger 6-3, 7-6 (3).

Bautista Agut next faces Robin Haase of the Netherlands, who defeated Joao Sousa of Portugal 4-6, 7-5, 6-4.

American qualifier Denis Kudla also progressed by beating Lukas Lacko 6-4, 6-4.