Andy Murray won his first match at the ATP event in Stuttgart on Tuesday, while Nick Kyrgios made a triumphant return after sitting out the European clay-court season.
Murray overcame a slow first-round start on grass as he defeated Christopher O'Connell 6-4, 6-3 and Kyrgios dominated Czech youngster Jiri Lehecka 7-6 (7/3), 6-3.
The colourful Australian barely had enough gear to make it onto court, with his tennis bag showing up on Monday while his all-important grass shoes only arrived at the tournament site with an hour to spare before his match.
"I had to play doubles in clay-court shoes yesterday," said Kyrgios, who has partnered up with Alexander Bublik. "I had to deal with a bit of adversity.
"Today was the first time I wore grass-court shoes.
"I didn't have the best preparation for here. I did hit on grass back in Australia, but there is nothing like a match.
"I've never needed match play to perform, I know what I have to do to win."
Former world number one Murray, now ranked 68th, is back in his element on the grass and can hardly compare his current confidence with his low point of a year ago.
"It feels completely different," the 35-year-old said after his victory 116th-ranked Australian qualifier O'Connell.
"Last year I was barely training before Queen's and when I was training I was not moving well.
"I also entered Queen's at the last minute, had an issue with a nerve in my leg and just didn't feel great."
But that unfortunate situation is now well in the past for the three-time Grand Slam champion.
"This year I've trained three weeks on grass and had good sessions," the Stuttgart debutant said.
"I've had some good matches (last week in Surbiton) and a good build-up for Wimbledon."
Murray delivered seven aces at the Weissenhof Club - whose grass was originally curated by Wimbledon groundsmen - and broke his opponent four times.
"I'm very motivated right now," said Murray. "That comes from loving the sport. You have to be willing to play through some pain.
"But it's a lot easier to do that when you are competing for major titles."
Top seed Stefanos Tsitsipas, who begins play Thursday after a bye, is determined to improve his grass-court standing after losing in the Wimbledon first round in three of four visits.
"I'm not where I want to be on the surface. But I have the right intentions - I'm fully present and committed to my job on court," the world number five said.
"I'm trying to get as many points as possible from each surface. I got a lot of clay points this spring (Monte Carlo title defence and Rome final) and I want to try and do the same on grass."
Tsitsipas starts against Swiss qualifier Dominic Stricker, the 2020 French Open junior champion who defeated American Maxime Cressy 6-7 (2/7), 7-6 (7/5), 7-6 (7/2).