Ageless Japanese veteran Kimiko Date-Krumm on Tuesday became the oldest woman to win a main draw match at the Australian Open, and she attributed her longevity to living a simple life.

The Japanese No 1, who is 42, crushed 12th seed Nadia Petrova, who is 12 years younger, 6-2, 6-0 in just over an hour in hot conditions on an outside court at Melbourne Park.

In doing so, she surpassed Britain's Virginia Wade as the oldest main draw winner. Wimbledon champion Wade won in 1985 when she was 40 years, 138 days.

Date-Krumm, a former world No 4, still has a way to go to become the oldest winner at a Grand Slam.

That record is held by Martina Navratilova, who was 47 when she won a match at Wimbledon in 2004.

But the Japanese star, ranked 100, has no plans to call it quits just yet.

"Of course I'm very happy to win today, but I don't play for the record. Even when I'm losing, I'm still enjoying it. Of course, every time I lose, it's mental, it's tough," she said.

"But still I'm enjoying playing. Forty-two, it's just a number."

Date-Krumm said simple living was the key to staying on top of her game when others players of her era have long faded away.

"I just eat a lot, I sleep a lot. Last night I was in bed before 10 pm, I finished dinner at 7:30 pm. I sleep before 10 pm like the kids," she said.

"Because always after the match or after practice I'm tired, so I need time to recover a lot. So I sleep a lot, I eat healthy foods, I drink a lot. It's simple life. That's it. Nothing special."

Date-Krumm made her WTA and Grand Slam debut in 1989 - when many current players were not even born - but hung up her racket in 1996 before launching a comeback in 2008.

Her victory on Tuesday was her ninth over a top-20 player since coming out of retirement. In 2010, she beat Australia's Samantha Stosur to become the first 40-something to beat a top 10 player.

"I've been playing Grand Slams many times since I came back, but I always have a tough draw," Date-Krumm said.

"Almost every time I play a seeded player - many times I almost beat them, and I lost many times too. This time when I saw the draw, I thought to myself, 'It's happening again'."

Despite the ranking gap between her and Petrova, Date-Krumm's consistent ground game, which produced 17 winners to 18 errors, made the difference.

"I'm playing for fun, because I like the game, but I don't want to lose," she said. "But even if I lose some matches, the next day when I wake up in the hotel I never think, I don't want to go practice.

"Every day now I want to go to practice."