Angelique Kerber and Ana Ivanovic got their Pan Pacific Open campaigns under way with straight-sets wins in Tokyo on Wednesday.
Both Kerber and Ivanovic suffered disappointing campaigns at Flushing Meadows, bowing out at the second and third-round stage respectively at the US Open.
The pair were the highest seeds in action at the WTA Premier hard court event and both progressed safely into the quarter-finals in relatively straightforward fashion with top seed Kerber edging Elina Svitolina 6-4 6-4 and Ivanovic overcoming Victoria Azarenka.
Kerber took on Svitolina for the first time since the Australian Open last year and again the German came out on top, although she was made to work by an opponent ranked 27 places below her.
Having eventually managed to shake off some dogged resistance from the Ukrainian to move ahead in the match, Kerber was required to come back from 3-1 down in the second set to progress in an hour and 26 minutes.
Third seed Ivanovic enjoyed a more comfortable success as she saw off Azarenka 6-3 6-4 to ensure her first victory over the Belarusian since 2010.
The world number 25 had won her last four meetings with Ivanovic, but came up short as the Serbian booked a quarter-final meeting with Lucie Safarova.
Sixth seed Dominika Cibulkova was made to work hard for her last-eight berth by American Coco Vandeweghe before the Slovakian won through 7-6 (7-5) 7-5.
The first set saw 10 dropped service games before going to a tie-break, which Cibulkova eventually clinched after missing three consecutive set point opportunities.
After Cibulkova capitalised on the fourth, Vandeweghe made five double faults in the second set, allowing her opponent to move into the next round where she will face Kerber.
In her first competition since reaching the quarter-finals at the US Open, Swiss wildcard Belinda Bencic missed out on the last eight as she blew a one-set lead against Safarova.
The 17-year-old made a bright start in her first career meeting with the Czech, but Safarova proved too strong, serving 10 aces on her way to a 3-6 6-4 6-2 victory.