Roger Federer returned to action at the Halle Open on Monday and won his first match on grass since the 2019 Wimbledon final.
Federer has endured two torrid years on the ATP Tour, missing most of 2020 due to double knee surgery.
The 20-time grand slam champion had then been limited to six matches this season heading into this week.
Having finally found some momentum at the French Open, Federer withdrew from his fourth-round match and explained: "It's important that I listen to my body and make sure I don't push myself too quickly on my road to recovery."
But the Swiss great was fit to finally step back out on a grass court for the first time since coming up short against Novak Djokovic at the All England Club.
And it was a winning return as Federer battled past Ilya Ivashka 7-6 (7-4) 7-5 in Germany.
Ivashka squandered two break point opportunities early in the opener and was quickly on the back foot after the set went to a tie-break, saving three set points but not a fourth.
Federer stayed patient in a second that stayed on serve initially, belatedly piling on the pressure to break in the final game having earlier passed up a match point at 5-4.
Fifth seed Federer was the only seed to win on Monday, however, as Sebastian Korda upset Roberto Bautista Agut in straight sets and David Goffin gave Corentin Moutet a walkover.
There was a standout shock at the Queen's Club Championships, too, as talented teenager Jannik Sinner was pipped by home hopeful Jack Draper 7-6 (8-6) 7-6 (7-2).
Draper's compatriot Cameron Norrie joined him in the last 16, battling back to beat Albert Ramos-Vinolas in three.