Roger Federer brushed off the cobwebs from his three-month break to book a Stuttgart Open quarter-final on Wednesday, although he was given a scare by Mischa Zverev.

Zverev took the opening set in their second-round clash but Federer eventually found his rhythm and began to look comfortable on grass.

Having battled back to level the match, Federer dominated the deciding set to book a last-eight berth against either Prajnesh Gunneswaran or Guido Pella.

"It feels good to win again," Federer said after his 3-6 6-4 6-2 win. "I've lost my last two matches, so it's nice to get a fresh start here."

He is joined in the quarters by second seed Lucas Pouille, the Frenchman ending teenager Rudolf Molleker's dreams of a second Tour win in emphatic style.

Pouille's 6-3 6-4 victory sets up a meeting with Denis Istomin after the Uzbek beat Florian Mayer 6-3 6-4.

Wednesday also saw first-round victories for Milos Roanic, Max Marterer, Benoit Paire and Feliciano Lopez, while Gunneswaran sent sixth seed Denis Shapovalov packing.

At the Rosmalen Grass Court Championships, defending champion Gilles Muller bowed out in the second round against Matthew Ebden.

Unseeded Australian Ebden stunned the 2017 winner with a 6-3 7-5 victory, setting up a last-eight meeting with Marius Copil – who beat Yuichi Sugita on day six.

Ebden's compatriot Bernard Tomic was also celebrating after he beat Robin Haase 6-3 7-5, while Fernando Verdasco is also a quarter-finalist after dispatching Daniil Medvedev in straight sets.