The second-seeded Stefanos Tsitsipas defeated Benjamin Bonzi 7-6 (1), 1-6, 6-3 in the first round of the Halle Open on Tuesday, when there were also wins for Felix Auger-Aliassime and Nick Kyrgios.
Tsitsipas, who reached the quarterfinals in Stuttgart last week, had to fight hard to beat the 52nd-ranked Bonzi in 1 hour, 55 minutes to take his tour-leading tally to 36 wins in 2022.
Tsitsipas is bidding for his second title of the year and his first on grass. The Greek player next faces Kyrgios, the Australian wild card who defeated Daniel Altmaier 6-3, 7-5.
The fourth-seeded Auger-Aliassime defeated Marcos Giron 6-3, 5-7, 6-3 for a second-round clash with the sixth-seeded Pablo Carreno Busta, who defeated Danish teenager Holger Rune on Monday.
Sebastian Korda defeated Cristian Garin 6-2, 6-3 but fellow American Maxime Cressy lost 6-4, 4-6, 6-4 to the fifth-seeded Hubert Hurkacz.
Also, Dutch qualifier Tallon Griekspoor battled to a 7-6 (10), 6-3 win over Alex Molcan.