A massive rainstorm left Roger Federer's return to tennis hanging, with the Swiss player and American teenager Taylor Fritz halted at 4-3 on Wednesday in their second-round match at the Mercedes Cup.
The weather intervened in a big way, forcing cancellation of the rest of the day's programme at the hilltop Weissenhof club.
The 34-year-old Federer is competing for the first time since losing to Dominic Thiem in Rome a month ago while plagued by back pain.
The Swiss skipped the French Open and spent three weeks in putting himself right with his coaching and medical teams.
"Unfortunately we can't play today anymore, too much of this stuff," he wrote on Twitter, followed by several rain-related emojis. "See you tomorrow @MercedesCup."
Federer made a return to Germany's car-making capital a decade and a half after last playing in the city, at the then-Masters event indoors.
His outing on the lawns prior to Wimbledon is his first at this event, which switched surfaces a year ago and scored big at the box office by signing Federer to a two-year appearance contract.
Fritz, aged 18, idolized Federer as a youngster and is seeking a first victory over a top 10 player after standing 0-2.
The pair went through a training session last summer when Federer issued an invitation to the youngster at the All England Club.
Federer left the Stuttgart court after breaking Fritz when the skies erupted.
The match will resume on Thursday after third seed Thiem, now ranked seventh after the French Open semi-final, begins his grass week against Australian Sam Groth.
Second seed Marin Cilic was also caught out by the rain, his match against qualifer radek Stepanek never even making it to a court.
Two Germans advanced before the storm moved through.
Seventh seed Philipp Kohlschreiber used an explosion of late-match energy to best advantage after missing match points in his eventual 7-5, 6-3 defeat of American Denis Kudla.
"I'm very happy to have won," the German number one said. "Of course (missing match points) bothered me. I showed some emotion - I'm also human."
Florian Mayer, who missed a year with a knee injury several seasons ago, moved into his first quarter-final in a year as he defeated compatriot Michael Berrer 6-3, 3-6, 6-4.