CINCINNATI (AFP) — Iga Swiatek shrugged off lingering weariness to partner Casper Ruud to back-to-back victories in the revamped mixed doubles competition of the US Open on Tuesday.

Swiatek — who had battled through a two-hour tussle with Jasmine Paolini to win the Cincinnati Open — looked full of energy as she and Ruud powered into the semifinals.

Swiatek and Ruud needed just 39 minutes to dispatch the US pairing of Madison Keys and Frances Tiafoe 4-1, 4-2 in their opening game at Arthur Ashe Stadium, and then reappeared roughly 20 minutes later to defeat Caty McNally and Lorenzo Musetti 5-3, 4-2 in their quarter-final clash.

The victories capped a gruelling 24 hours for Polish star Swiatek, who hot-footed it to the airport after Monday’s win in Cincinnati and only arrived at her hotel in New York in the early hours of Tuesday.

“Honestly, the last two days have felt like one day, but I’m super happy to be here,” Swiatek said, adding that her tight turnaround had helped her unwind after her exertions in Cincinnati.

“Honestly, I think actually it’s kind of nice for the recovery,” Swiatek said.

“To have another task and to not let yourself be lazy but also focused on the next exciting thing.”

Ruud and Swiatek had just enough time to fit in a quick practice before taking to the court in their first match as a doubles pairing.

“I was happy to team up with Iga,” Ruud said afterwards.

“She’s on the winning train these days so I’m just jumping on the train and let’s see if we can win some more before the mixed doubles is over.”

“I think everyone should show some appreciation to Iga today. She only got to her hotel 12 hours ago at 2:30 a.m., and she’s here playing.”

Swiatek and Ruud will meet top seeds Jessica Pegula of the United States and Britain’s Jack Draper in Wednesday’s semifinals.