MELBOURNE, Australia - Polish teenager Iga Swiatek sealed a spot in the fourth round at a Grand Slam for the second time in less than a year at the Australian Open on Saturday with a 7-5, 6-3 upset of No.19 seed Donna Vekic. 

Playing her first tournament since foot surgery that ended her 2019 season following the US Open, the 18-year-old advances to the fourth round at a Slam for the second time -- following her breakout run to the round of 16 at the French Open last June -- in just her fifth major main draw appearance. 

It was a largely commanding performance from Swiatek over the course of one hour and 44 minutes, though she needed to rally from a break down in the second set and sealed the match by winning the last five games.

"I wasn't so confident in my first year on tour," she told reporters after the match. "But now I feel belong and have everything I need to play against the best players." 

In the opener, the two players traded holds of serve over the first 11 games, with Swiatek the first of the two to save break points. The World No.56 saved one in the very first game of the match, and erased three crucial chances for Vekic to break at 3-3, before converting on her second break - and set - point in the final game. 

Vekic did not let break points in the opening game of the second set pass her by, however, as she finally converted her sixth chance of the match overall and saved a pair of break points against her to build a 2-0 lead to start the second set.

Crucially, however, Swiatek did not allow the World No.20 a second break of serve, as she denied Vekic three more opportunities in the third game before getting on the board.

The teenager started to move into the ascendancy from there, and eventually got the set back on serve in the sixth game before scoring the decisive break in the eighth.

Swiatek served six aces and hit 29 winners in the match and lost serve only once, saving eight of the nine break points she faced, while Vekic racked up 32 unforced errors to just 18 winners.

"It was my toughest match so far," said Swiatek. "Playing against such an experienced player is always hard. I wasn't that confident before the match. I was really tired after the first two matches so it was hard from every point of view. I was just trying to play one more ball."

The Polish No.2 is one of two teenagers left in the women's singles draw alongside 15-year-old American Coco Gauff, and after beating Vekic in their first-ever meeting, the teenager will next square off against a second consecutive seed.

She next faces No.28 Anett Kontaveit after the Estonian blitzed No.6 seed Belinda Bencic with the loss of just one game in under an hour.


2020 Australian Open Highlights: Swiatek soars past Vekic