SYDNEY (Reuters) - Top seed Samantha Stosur crashed out of the second round of the Brisbane International on Tuesday, losing 6-2 6-4 to Jarmila Groth in a battle of Australia's top two women.

Spanish third seed Fernando Verdasco was also upset in the men's tournament, losing his first round match 6-1 6-7 6-3 to Germany's Benjamin Becker.

Top seed Robin Soderling of Sweden had no such problems, however, reaching the second round comfortably with a 6-2 6-4 humbling of American qualifier Ryan Harrison.

World number six Stosur is considered her country's best hope of ending a 32-year wait for a home grand slam champion at the January 17-30 Australian Open.

Big-hitting Groth never let last year's French Open finalist settle, however, and raced away with the first set on the back of seven aces.

Stosur fought back in the second to take a 4-2 lead but Slovakia-born Groth won the next four games in a row to claim local bragging rights and a place in the third round.

Verdasco, a semi-finalist at the Australian Open in 2009, recovered from a listless start to grind out the second set but had few answers in the third as Becker played a faultless service game to seal the match in just over two hours.

"I had a good game plan and it worked well today," 53rd-ranked Becker said after setting up a second round match with Colombia's Santiago Giraldo.

"It is always good to get a win under your belt ... and its not every day you beat a top 10 player."

After beating Frenchman Jo-Wilfried Tsonga in the final at Kooyong last year, the feisty Spaniard advanced to the fourth round at Melbourne Park but was edged in a five-set thriller by Russia's Nikolay Davydenko.

Twice French Open finalist Soderling took just 65 minutes to dispatch 18-year-old Harrison, facing and saving just one break point and sealing the victory with his eighth ace of the match.

The world number five will be hoping for better luck this year at Melbourne Park, where he has never been past the second round and made a first round exit last year.

Women's second seed Shahar Peer of Israel also went out earlier on Tuesday, losing 3-6 6-1 7-5 to Lucie Safarova of the Czech Republic in their second round tie.

Italy's Flavia Pennetta was forced to withdraw from the tournament due to a gastrointestinal illness.

(Reporting by Ian Ransom in Melbourne and Nick Mulvenney; Editing by Alan Baldwin)