Roger Federer found his rhythm after a slow start to beat Mischa Zverev in his first match for three months at the Mercedes Open.
The Swiss, playing for the first time since March after skipping the claycourt season, won 3-6 6-4 6-2 on the Stuttgart grass.
Federer missed several chances to break the Zverev serve before dropping the opening set, but broke the German twice in both the second and third to win in one hour and 33 minutes.
It has been 80 days since Federer’s last match, a defeat against Thanasi Kokkinakis in Miami, which followed a loss to Juan Martin del Potro in the Indian Wells final.
“Three months is a long time, it’s longer than the year-end break,” said the 20-time Grand Slam champion.
“So I’m very happy returning on good terms onto the tour. It was difficult, I missed some chances maybe in the first set. He connected well at the right times.
“And then I found a way, I found my rhythm. I’m very happy with how I played. I’m super happy to be back on tour. It’s been a great start.”
Federer, who would replace Rafael Nadal as world No.1 if he reaches the final in Germany, will play Argentina’s Guido Pella or Prajnesh Gunneswaran of India in the last eight.
Gunneswaran was a surprise 7-6(6) 2-6 6-3 winner over Canadian sixth seed Denis Shapovalov.
“It feels good to win again,” added Federer.
“I’ve lost my last two matches,” added Federer. “It’s nice to get a fresh start here.”
13 October 2018
Three-times Shanghai Masters champion Novak Djokovic extended his winning streak to 16 mat... More
7 October 2018
Caroline Wozniacki is the China Open champion, winning the title with a 6-3 6-3 victory ov... More
16 October 2018
How well do you know the birthdays of some of the world's best players? It's time to find ... More