Second-seeded Angelique Kerber beat two-time Wimbledon champion Petra Kvitova in straight sets to reach the US Open quarter-finals for the first time since 2011.
Kerber won 6-3 7-5 on Sunday in a match-up of left-handers to set up a meeting with last year’s runner-up, Roberta Vinci.
The German made her first major semi-final at Flushing Meadows five years ago, but this season came an even bigger breakthrough when she beat Serena Williams for the Australian Open title.
Kerber could overtake Williams for the No.1 ranking depending on their US Open results.
Kvitova hadn’t made it past the third round at the first three majors of the year but was coming off an Olympic bronze medal in Rio de Janeiro, where Kerber won the silver.
The 14th-seeded Kvitova had 43 unforced errors and seven doubles-faults – the last coming on match point.