Jessica Pegula’s rout of world No. 1 Iga Swiatek at the United Cup in Sydney on Friday has placed the United States in a dominant position to progress to the final of the mixed teams event.

The American defeated Swiatek 6-2, 6-2, leaving the world’s top-ranked woman sobbing afterwards as she struggled to cope with the magnitude of what was a rare defeat over the past 12 months.

Frances Tiafoe later gave the U.S. a 2-0 lead over Poland in the first semifinal by defeating Kacper Zuk 6-3, 6-3 in a convincing display at Ken Rosewall Arena.

Taylor Fritz can clinch a spot in the final for the U.S. when he plays world No. 10 Hubert Hurkacz in the third singles to open play Saturday.

Swiatek had won all four of clashes against Pegula last year and was considered a dominant favorite for the Australian Open beginning on Jan. 16.

But the assertive play of Pegula, who adopted an aggressive position when returning Swiatek’s serve, reaped rich rewards for the world No. 3 in what proved a mismatch.

The 28-year-old, who reached quarter-finals in three Grand Slam tournaments last year, said she benefited from her familiarity with Ken Rosewall Arena and the swiftness of the court.

The U.S. was based in Sydney during the group stages of the inaugural tournament, while the Swiatek-led Poland progressed from the Brisbane section of the 18-nation event.

With her head covered by a towel as she sat alongside Poland’s captain Aga Radwanska, Swiatek cried as she listened as her rival explained why the conditions suited her.

“I played her in a lot of different places but … these were definitely the fastest conditions,” Pegula said. “I am also aware they had a quick turnaround (on Thursday) flying here, where we have been lucky enough having maybe a little bit of an advantage being used to the courts.

“I wanted to take that as much as I could and use it as much as I could and I thought I did a really good job of playing aggressively, serving smart and returning really well.”

Pegula started extremely well by breaking her rival’s serve in the first game in a pointer of what was to come in the clash between two of the world’s leading women.

Her aggression on return was notable, with Pegula stepping well into the court and taking the ball early, which placed the serve of the reigning French and US Open champion under significant pressure.

Swiatek took a lengthy toilet break at the end of the first set and was able to edge ahead for the first time when holding her opening service game to start the second set.

But that did not change the tenor of the match, with the American holding her rhythm in an impressive display before Tiafoe outclassed Zuk to maintain his unbeaten record in the United Cup.

Greece will play Italy in the other semifinal, with the first two singles matches scheduled for later Friday. Maria Sakkari is scheduled to lead things off for Greece against Martina Trevisan of Italy, with Greece’s Michail Pervolarakis set to play Italian Lorenzo Musetti in the men’s singles.