Stuttgart, Germany, 10 June 2015 | AAP

Bernard Tomic has opened his grasscourt season with a win, downing German Jan-Lennard Struff at the Mercedes Open in straight sets.

Later on Tuesday, fellow Aussie Sam Groth joined Tomic in the second round when opponent Sergiy Stakhovsky retired in the third set.

Tomic enjoyed a 6-3 7-6(5) victory over the local hope and will take on the winner of the Mikhail Kukushkin-Tommy Haas match.

The victor of that second round clash looks likely to draw a quarterfinal match-up with Rafael Nadal.

“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, 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 grasscourt events to defend points from.

Meanwhile, Groth advanced when the ailing Stakhovsky called it quits with trailing 4-6 7-5 5-3, as Groth prepared to serve for the match.

The Victorian has now won six straight matches on grass following his victory at last week’s ATP Challenger event in Manchester.

Next up for Groth is third seed Feliciano Lopez.