Johanna Konta booked her passage into the quarter-finals of the Apia International with a straights sets win over Dario Gavrilova.
Konta succeeded where a number of top seeds failed as she brushed aside her opponent 6-1 6-3 to make it through to the last eight.
Earlier world number one Angelique Kerber was defeated by Daria Kasatkina, while Dominika Cibulkova and Svetlana Kuznetsova, seeded third and fifth respectively, had also crashed out earlier on Tuesday.
There were no such problem for Konta though after she broke Gavrilova in the opening game and went on to drop only four points on serve when dominating the first set.
Gavrilova made more of a fist of it in the second set and managed to fight off four match points on serve in the eighth game, before the British number one finally won through.
"I knew going into the match it was going to be an incredibly tough one, she's one of the best fighters on tour," she said.
"It's such a strong tournament, such depth, I know going into every single match that it's going to be a tough one and I'm just going to have to, first and foremost, take care of things my end."
The sixth seed continues her preparations for next week's Australian Open with a last-eight clash against Kerber's conqueror Kasatkina, the Russian ranked 16 places below Konta at 26 in the world.