Garbine Muguruza's China Open defence came to an end in the third round with a 6-1 6-4 defeat at the hands of Petra Kvitova.
Second seed Muguruza has struggled for form since winning the French Open in May, a semi-final appearance at Cincinnati in August her best performance since.
Her inconsistency continued with Kvitova, who came into the tournament on the back of claiming the Wuhan Open title, triumphing comfortably in Beijing in 74 minutes.
CLINICAL KVITOVA TO FACE KEYS IN QUARTER-FINALS
It was a shaky start for Kvitova as she faced a break point in the opening game of the match, but after staving it off she converted the first two that came her way to build a 5-1 lead.
The Czech held to love to take the first set, and her serve proved key to getting her through the second with Muguruza only able to claim three points when returning.
Kvitova's opponent in the quarter-finals will be Madison Keys after the American fought back from an early deficit to triumph 7-6 (7-2) 6-2 against Svetlana Kuznetsova.
Eighth seed Keys dropped her serve twice to fall 5-2 behind, fending off set point in game eight before pulling a break back and marching on to victory.
KERBER SETS UP SVITOLINA CLASH
World number one Angelique Kerber was made to work by Barbora Strycova but booked her place in the third round with a 6-3 7-6 (7-4) victory.
The German failed to consolidate her opening break but did so at the second attempt, holding serve to take the advantage.
A topsy-turvy second set saw seven breaks of serve, two of which stopped Kerber from seeing out the match, but she was not to be denied in the tie-break.
She said: "The match was on a really high level at the end of the second set. We run a lot, both of us. I think we both have a great return, so I think that was also the key from both of us to breaking back."
Elina Svitolina awaits in the third round after the Ukrainian dispatched wildcard Sabine Lisicki 6-4 6-4.
KONTA READY TO NEUTRALISE PLISKOVA
Johanna Konta defeated Timea Babos 7-5 6-2 to set up a third-round match with Karolina Pliskova, who was forced to come from behind to eliminate Daria Kasatkina 3-6 7-5 7-6 (9-7) after saving a match point in the tie-break.
Konta knows she is in for a difficult match against the Czech but already has a gameplan in mind.
She said: "I'm yet to beat her so I'm definitely looking forward to the challenge. Every time we've played we've had some tough battles, close matches, so I'll go out there and try my best.
"I think with Karolina she has an incredible serve so already you go into the match with the challenge of trying to neutralise that and get yourself into her service games.
"It's about neutralising as best you can but also being on your toes to exploit any opportunities you do get."