Bernard Tomic has opened his grass court season with a win, downing German Jan-Lennard Struff at the Mercedes Open in straight sets, while compatriot Sam Groth also advanced.
The fifth-seeded Tomic enjoyed a 6-3 7-6 (7-5) victory over the local hope and will take on 37-year-old Tommy Haas.
The victor of that second round clash looks likely to draw a quarter-final match-up with Rafael Nadal.
Groth was victorious when his Ukranian opponent Sergiy Stakhovsky retired with defeat in sight, bowing out with the Australian serving for the match up 4-6 7-5 5-3.
“Unfortunately today after 1st set my back started to get tight,” Stakhovsky wrote on Twitter.
“And by the 3rd it was gone. I was waiting for Sam to break so I can retire.”
Tomic, ranked a career high No.24 in the world and seeded fifth in Stuttgart, has another chance to push up the rankings over the coming months with only three second round appearances at grass court events to defend points from.
“It’s very exciting for me to be back here,” said Tomic, who was born in Stuttgart.
“My first match on grass was pretty good. I served and returned well in the first set.
“I think I lost a little bit of concentration in the second. It’s all about finding your movement on the grass in the first match and I felt like it was pretty solid.”
Tomic will next play Haas, who is making his comeback after a shoulder injury and defeated Mikhail Kukushkin 6-4 7-5 in his first match in a year.
In other games on Tuesday, Eighth-seeded Viktor Troicki beating Croatian teenager Borna Coric 6-2 6-0, while Marcos Baghdatis, Andreas Haider-Maurer and Andreas Seppi also won.