World No.1 Iga Swiatek was reduced to tears after losing 6-2. 6-2 to Jessica Pegula as Poland trail the US 2-0 in the United Cup semi-finals in Sydney.

Swiatek, straight-sets winner of three group matches at the new competition, blamed herself for her country’s dire predicament.

Teammate Kacper Zuk was beaten by peacocking American Frances Tiafoe 6-3, 6-3 to leave the Poles fighting for survival in Saturday’s wrap-up of the semi-final tie.

.”I just knew that I felt kind of helpless today, because physically and mentally I wasn’t able to kind of show up even, and problem-solve,” Swiatek said.

“it’s always hard when you lose, especially when you’re playing for the team and your country.

“So I was just sad. But, you know, it’s not the first time I cried after a lost match. Nothing special.”

Pegula earned her revenge after losing four of her last five matches against Swiatek, winner of eight titles last season – including the French and US Opens.

Swiatek lost the first seven points of the semi-final as Pegula seized early momentum and held it throughout.

“Conditions today were totally different than in our previous matches,” Pegula said.

“Every other place I’ve played her has been pretty slow. I think that favoured me a lot, and I was able to use that to my advantage and play a really super clean match.

“I just was able to execute my game plan probably better than I have previous times.”