MELBOURNE, Australia -- Powerful. Unpredictable. Entertaining. Three words that encapsulate Jelena Ostapenko's aura and reputation, honed by her memorable victory as a 20-year-old at the 2017 French Open and the hot and cold career she has built since then. 

"With me, it's never boring on the court, so I think that's what the fans like," Ostapenko told reporters after her 7-5, 6-3 win over No.7 Coco Gauff in the fourth round of the Australian Open. 

The 25-year-old Latvian is one of the most feared hitters in the game precisely because she can take the racquet out of your hand. Her audacious penchant to skim the lines when a more conservative shot would suffice make her matches an irresistibly exciting edge-of-your-seat ride. 

Australian Open: Ostapenko ousts Gauff to make first Melbourne QF

"She hit a lot of winners, which not a lot of people can do on me," Gauff said. 

"There were balls I was hitting deep, and she was hitting them on the line and hitting them back deep, like, over and over again. It's just one of those days that just didn't go my way and went her way."

Seeded No.17 at Melbourne Park, Ostapenko is into her first Australian Open quarterfinal with wins against Gauff, Katerina Baindl, Anna Bondar and Dayana Yastremska. She has lost just one set so far and as she readies to face Wimbledon champion Elena Rybakina, the Latvian is finding the confidence and ball-striking that can unsettle the rest of the field.

After a contained opening win against Yastremska, Ostapenko has been full-throttle in her game since. She has hit more winners than unforced errors in her past three wins, including 30 against Gauff. She's seeing the ball early and terminating rallies immediately. Of her 375 rallies tracked by the tournament's statisticians, only 17 have lasted more than eight shots. 

Ostapenko credits the work she did on her footwork during the pre-season.

"Before, I was still hitting the ball hard, but I was not really stepping in the court," Ostpenko said. "Now I feel like I'm stepping much better in the court and taking the ball earlier, so I take time away from the opponents, which makes me a more dangerous player.

"I was working a lot on my movement and also the fitness and kind of everything."

But can Ostapenko redline her way to a second major title? Her game has been disruptive on natural surfaces, with a Wimbledon semifinal also on her resume. Yet before this fortnight, she had yet to progress to the fourth round at either the US Open or Australian Open, a surprising stat given three of her five titles have come on hard court. 

Ostapenko says it's just a matter of focus, to find the line between being too aggressive and not being aggressive enough. Walking that tightrope has been the story of her career. 

"If you feel really good, you can always step on the court and play well," she said. "But if you really have to play a little bit more rallies to get the points and then get into the game, then you can start to be aggressive.

"But sometimes I feel some matches, even if you are losing, you still have to be aggressive, and that's the key what gives you the win. Like the French Open final, for example. I kept being aggressive all the match, and it brought me at the end the win."

Ostapenko holds a 2-0 lead in the head-to-head over Rybakina. In fact, the Wimbledon champion has yet to take a set off her. A win would put her into her first major semifinal since 2018 Wimbledon. 

"I love to play on the big courts, so I really enjoy it and with a lot of fans," Ostapenko said. "With the good players I think I have nothing to lose, and I'll just enjoy it as much as possible.

"It's great to be in the quarterfinals. If I play my game, I think I have all the chances."