Iga Swiatek backed up her defeat last month of Sloane Stephens as the US Open top seed repeated the victory 6-3, 6-2 on Thursday to reach the third round.
No. 1 Swiatek beat the 2017 champion here in straight sets barely a fortnight ago at the Midwest run-up tournament in Cincinnati.
She now stands 46-12 at the Grand Slams.
“I’m happy with my focus,” the winner said. “I was solid from beginning to end.
“It was my first ever match on the Ashe court but I tried to have the same motivation as on any other court.
“That is the best way to perform well, I think.”
The 21-year-old Pole is seeking her seventh title this season in hopes of levelling with the lucky seven achieved by Serena Williams in 2014.
Stephens suffered her 10th loss at her home Grand Slam and has never beaten a world No. 1 in her last 10 attempts.
Main photo:- Iga Swiatek serves for victory in second round match – by Roger Parker International Sports Fotos Ltd
