MELBOURNE – Two-time Wimbledon champion Petra Kvitova is the first player through to the second round of the Australian Open at Melbourne Park.

The sixth-seeded Czech dispelled any lingering fitness doubts with a commanding 6-3 6-1 win over Thai qualifier Luksika Kumkhum in the opening match at Rod Laver Arena on Monday.

Kvitova pulled out of last week’s Sydney International with gastro, having also retired mid-match during the first round in Shenzhen earlier this month, her only other tournament appearance since the Fed Cup final in November.

“I had a great off-season with fitness and tennis preparation and when I got to China I got some stomach virus or something and I was just lying and going quite often to the toilet for eight to nine days,” Kvitova said.

“So I didn’t eat very well and I lost some weight and that’s why I withdrew from Sydney as well.

“But I’m feeling much better now.”

The world No.7 defied sweltering 30-plus-degree temperatures to blast 18 winners and five aces while dropping serve just once in an impressive 70-minute workout against Kumkhum.

“I’m very pleased with how I played today, how I handled the nerves and everything,” Kvitova said.

“First rounds are always very tough and for me it was my first match of the season so I’m really glad how I did.”

Kvitova next plays either rising Australian star Daria Gavrilova or fellow Czech Lucie Hradecka on Wednesday for a place in the last 32 of the season’s first major.