As the seeds continued to tumble at the Sydney International, world No.6 Petra Kvitova avoided the carnage to emerge as the title favourite.
Second-seeded Kvitova was the first woman through to the semi-finals after removing fellow Czech Lucie Safarova in straight sets on Wednesday to post her 300th career win.
The highest-ranked player left in the draw after Tuesday’s demise of top-seeded titleholder Agnieszka Radwanska, Kvitova advanced to the last four with a 7-6 (7-4) 6-2 defeat of Safarova.
Kvitova will now take on Tsvetana Pironkova for a place in the final after the Bulgarian qualifier caused yet another upset, defeating third-seeded Italian Sara Errani.
World No.107 Pironkova accounted for Errani, ranked 100 places higher, in straight sets 7-6 (7-2) 6-3.
Despite the likes of fellow top-10 players Jelena Jankovic and Caroline Wozniacki having made early exits Kvitova said she wasn’t at all worried she’d suffer the same fate.
“I wasn’t, no,” she said.
“I was trying to focus on my game, on my match, and not about the other seeds. They lost already.
“It’s still a tough tournament and a tough next round and that’s it.”
Pironkova, a one-time Wimbledon semi-finalist, needed just under two hours to dispose of Errani, who was sporting heavy strapping on her right thigh and took an injury time out in the second set to get treatment on her lower back.
Pironkova has yet to beat Kvitova in three previous encounters.
The Bulgarian said she wasn’t surprised to see most of the seeds eliminated and hoped to continue her giant-killing ways with victory over Kvitova as she eyes her maiden WTA title.
“This is sport; it’s tennis; everything can happen,” she said.
“All of the players who are participating here deserve to win. We all work very hard, and we show it out there.
“Petra is a very tough opponent definitely.
“I’ve played with her a few times and I still don’t have a victory, so I’m hoping for that.”
The other two quarter-finals, featuring Americans Bethanie Mattek-Sands and Madison Keys and German fifth seed Angelique Kerber against Spaniard Carla Suarez Navarro, will be played on Wednesday night.