It's 800 not out for Caroline Wozniacki.

The Danish star played her 800th WTA match today, as she rolled past Petra Martic 6-2, 6-2 in just 53 minutes, to progress into the quarter-finals of the ASB Classic.

It's an extraordinary number of matches, testament to her longevity and consistency over the years.

She's still only 27, but is entering her 13th full time season on the WTA tour.


"I guess that makes me feel a bit old," Wozniacki said with a laugh as she contemplated her landmark.

"It's a long time for sure."

She was arguably the form player on tour in the second half of the 2017 season, and has started 2018 well.

It might be the product of her evolving approach, to both the physical and mental side of the game, where she has learned that balance is key.

"I took five weeks off, didn't hit a ball at all and just kept my fitness up a little bit," said Wozniacki of her off-season. "Then I got on court and was excited to start playing and have really intense workouts. That's something I've learned over the years, to remember sometimes to just take a breather and then come back here."

"Every year you try something new and tweak it, if something works for you, you keep going with that thing. But the main thing I've learned is to not overwork, not over-practice. The older you get, you don't really need that as much."

The world No3 remains competitive, and often uses little incentives to spice up the endless practice sessions, a reality for professional tennis players.

"I love to compete, I love to be out there and playing for something," said Wozniacki. "I think it gets a little boring sometimes, being out on the practice courts and doing the same things over and over. At the same time, you have to do those things; you just learn to set goals and make it more fun to practice, playing for something — play for ice cream, candy. That motivates me."

Martic is no mug — she has made the second week at both Roland Garros and Wimbledon and been inside the top 50 — but the Croatian was left frustrated today by Wozniacki's power, placement and precision.

The Dane took the first set with relative ease, then weathered a brief second set storm as Martic found her way back into the match.

"It's good so far and I'm building on the game all the time," said Wozniacki. "I still have a little time before Melbourne so hopefully I can get some more matches here and build on it, feel better and better."

Wozniacki faces wildcard Sofia Kenin tomorrow, after the American prevailed over Varvara Lepchenko in three sets. The Dane doesn't know much about world No108 — having never faced her, or even seen her practice, but will rely on her father (and coach) to do some research before the match.

There was further good news for Wozniacki, as she will move up to No2 in the world next week, following Garbine Muguruza failure to progress beyond the second round in Brisbane.

"I guess I'm top-two seed now [at the Australian Open], depending on [Simona] Halep, I think," said Wozniacki.

"Slowly but steadily."