Alexander Zverev will play Holger Rune and Casper Ruud is set to face Alex Molcan in the round of 16 at the BMW Open.
Zverev and Ruud – the number one and two seeds respectively – received byes in the round of 32, with Danish wildcard Rune defeating Jiri Lehecka 7-6 6-3 to advance in Munich on Monday, and Molcan beating fellow Slovakian Norbert Gombos 6-1 3-6 7-6.
Teenager Rune had won his opening match in four of his past five tour-level events ahead of the tournament and extended that run with relative ease.
There were no problems for seventh seed Miomir Kecmanovic as he overcame Max Hans Rehberg in straight sets, 6-2 6-3, and he will face Daniel Altmaier in the last 16 after he beat his German compatriot Philipp Kohlschreiber 7-6 3-6 6-1.
Emil Ruusuvuori is also through after beating Japanese opponent Yoshihito Nishioka 7-6 7-5 and the Finn will now go up against the winner of Dan Evans and Maxime Cressy.
At the Estoril Open, Alejandro Davidovich Fokina, who reached the final in Monte Carlo earlier this month, will face fellow Spaniard Bernabe Zapata Miralles next after he overcame Federico Coria 6-4 6-3.
Fifth seed Frances Tiafoe secured a victory against Dusan Lajovic, with the American coming from a set down to win 2-6 7-5 6-0, and up next for him is Nuno Borges in the last 16.
Borges advanced after opponent Pablo Andujar retired hurt in the second set, although the Portuguese was already a set and 3-0 up at the time, while Soonwoo Kwon eased past Benoit Paire in straight sets.