TORONTO, Canada - Rising star Iga Swiatek scored one of the biggest wins of her young career on Wednesday night, dismissing former World No.1 and 2010 Rogers Cup champion Caroline Wozniacki, 1-6, 6-3, 6-4, to reach the third round in Toronto.

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"It's amazing. I'm feeling great. I mean, I'm really tired, and I should be sleeping right now!" a breathless Swiatek said during her on-court interview.

The 2018 junior Wimbledon champion roared into the second week of Roland Garros just two months ago, and appears poised for even bigger results after earning a second career Top 20 win - her first over a Grand Slam champion - in just about two hours on Centre Court.

"I'm not used to this!" she exclaimed as the crowd cheered her answers.

She later extolled the value of playing a more conservative brand of tennis than she is used to.

"I played out of my comfort zone," she admitted. "And I will play outside of my comfort zone for a few more matches if I choose those tactics because I just want to hit it hard. So hopefully, by the next tournament my comfort zone is bigger. I’m working with my coach to make my game a bit different, with a few more weapons, and I’m glad I could use the new one this time."

Qualifying for the main draw with solid wins over Shelby Rogers and Heather Watson, Swiatek endured a slow start against the experienced Wozniacki, who won the first three games and ultimately raced out to a 5-1 lead, taking the first set on her third opportunity.

Aiming to avoid a defeat similar to one she took against Simona Halep in Paris, the 18-year-old soon turned the tables on the Dane, scoring the first break of the second set. She saved two break points in the following game to maintain her lead, ultimately holding on to level the match.

"It was really tough. I was really nervous at the beginning, I was nervous during the whole match. I just tried to compete at my best, put the ball in the right place in the court and not take too many risks because that was the main mistake I made at the French Open when I played against  Halep," she confessed. "I’m glad that I did it. I didn’t make as many mistakes in the second and third sets as I did in the first.

"I thought about the tactics a lot with my coach. I’m a power player and it’s not the best thing to use pure power against her because usually you just end up playing even faster. I tried to play top spin high over the net and let Caroline make the mistakes."

Wozniacki seemed back to her best early in the decider, taking the first three games as she did to start the match. Swiatek nonetheless fought back, rolling through the next three grames to tie things up and soon found her chance in an all-important ninth game.

Showing impressive maturity, Swiatek shook off missing her first two match points to convert her third and seal her spot in the Round of 16.

In all, she displayed encouraging aggression and even stats, finishing with 34 winners to 33 unforced errors, converted three of five break point opportunities. Up next for the Pole is reigning US and Australian Open champion, Naomi Osaka, who won the first set against Tatjana Maria before the German was forced to retire due to a left abdominal injury.

"Ooh!" she laughed. "It's going to be exciting. Naomi is a great player, already a legend. I just want to do my best and give a show. Even if I lose, I hope to show my best tennis and that that's possible."

Regardless of the outcome of her next match, it's been a week to remember for the teenager.

"It’s amazing," she added. "Last season, I only played clay, hard court was tricky for me. The fact I’m playing well here is great for me."