Stuttgart, Germany: Roger Federer made a winning return to tennis on Thursday after a month away with back pain as he finished off a Stuttgart ATP grass-court match 6-4, 5-7, 6-4 over teenager Taylor Fritz.
The pair were called off court in the second round on Wednesday as heavy rains raked the Weissenhof Club, with the Swiss leading 4-3.
Federer, who last played in a third-round Rome loss to Dominic Thiem, then missed the French Open, is building for another run at Wimbledon, where he is a seven-time champion.
The world number three is making his first appearance in Stuttgart since 2001, when he played the indoor Masters.
"I got the feel of playing matches again," Federer said. "It was also good to see how the body reacted. The match was short but I felt good -- no tension.
"But my energy level was up and down, it's a good thing I found it again at the end. I was wondering where it went during some of the match.
"It just felt good to be back on the match court."
The 34-year-old reached another milestone as his defeat of the young American hopeful marked his 1,071st victory, tying him in second place with Ivan Lendl for the Open era win record.
American Jimmy Connors holds the all-time record of 1,256 victories.
Federer will next face German Florian Mayer, a qualifier.
Fritz, the 18-year-old world number 65, made a match of it as he played toe-to-toe with the 17-time Grand Slam winner, who badly needs match play before Wimbledon starts in just over a fortnight.
Federer finished off a 29-minute opening set but found himself in a battle in the second as Fritz began gaining confidence.
The youngster broke to level matters in the final game of the second set after Federer had saved three set points.
In the third, the Swiss top seed broke for 5-4 as Fritz lost a 40-15 lead with four consecutive errors.
Federer secured the victory after one hour 40 minutes on court, having saved eight of nine break points faced.
Fritz was pleased with his own showing.
"If I'd known I would take a set off of Federer I would have been pretty happy," Fritz said. "I had mixed emotions for sure.
"I have great respect for Federer, but I also showed I was not afraid to test him by winning the second set and trying to win the match -- I hung in there.
"It was Federer (out there), but I wasn't afraid to try and take the match. I came up with some good shots in tough situations -- it was pretty good for me."
Czech veteran Radek Stepanek stunned second seed Marin Cilic 7-6 (7/4), 7-5 to eliminate the Croatian at the first hurdle.
Argentine Juan Martin del Potro needed four match points to finally tame Australian John Millman 6-4, 6-4.
Del Potro, whose good friend Rafael Nadal withdrew from Wimbledon to let a wrist injury heal, said that his own recovery form long-term wrist problems is progressing at a measured pace.
"I have to be patient, it can be frustrating. You want to hit hard on the grass. But this is only my first grass week and I have to deal with that and my wrist recovery.
"In the end, I played some good tennis. This is a special monent for me after not playing on grass since 2013.
"If you start well and hit hard on this surface, you have a chance to win."
Third seed Thiem defeated Sam Groth 7-6 (7/3), 7-6 (7/2) despite the Australian sending down 21 aces.
Thiem will line up in Friday's quarter-finals against Mikhail Youzhny after the Russian beat Sergiy Stakhovsky 6-3, 7-6 (7/1).
French fourth seed Gilles Simon beat Germany's Jan-Lennard Struff 6-4, 4-6, 6-2.