Top seed and two-time defending champion Jo-Wilfried Tsonga and sixth-seeded American Sam Querrey were a pair of second-round winners, while fifth-seeded Frenchman Benoit Paire suffered an opening-round upset Wednesday at the $545,000 Moselle Open tennis event.
Tsonga, playing his first tennis since late June, handled fellow Frenchman Edouard Roger-Vasselin 6-3, 6-4 on the indoor hardcourts at Parc des Expositions.
The former Australian Open runner-up Tsonga beat this week's third seed, Italian Andreas Seppi, in last year's finale in Metz.
His quarterfinal opponent on Friday will be German Tobias Kamke.
Meanwhile, German Benjamin Becker upended Paire in 6-3, 7-5 fashion and the 6-foot-6 Querrey was leading oft-injured Frenchman Paul-Henri Mathieu 6-2 after one set when Mathieu retired with a right leg injury on Day 3. The wild card Mathieu was a runner-up here five years ago.
Another second-rounder saw the aforementioned Kamke overcome Hungarian qualifier Marton Fucsovics 1-6, 6-3, 6-2.
In some other first-round action, French wild card Albano Olivetti defeated German qualifier Mischa Zverev 7-5, 7-6 (7-3), France's Nicolas Mahut bested Argentine Leonardo Mayer 7-6 (7-2), 6-4, and Argentine Carlos Berlocq dismissed Czech Jiri Vesely 6-3, 6-4. Zverev was the Metz runner-up in 2010.
The 2013 Metz champion will collect $98,000.