Venus beats Azarenka in Tokyo
Venus Williams produced arguably her best display in three years to beat Victoria Azarenka to reach the last 16 of the Toray Pan Pacific Open.
Unseeded Williams, who at 33 years old is now ranked 63rd in the world, had not claimed such a scalp since she last beat the Belarusian in the final of the Dubai Tennis Championships back in February 2010.
This time around the nine-time grand slam winner needed just 35 minutes to take the first set in Tokyo before resisting her rival's fightback to triumph 6-2 6-4.
It was a third career defeat to the elder Williams sister - competing in Japan while Serena Williams recovers from fatigue - for world number two Azarenka, who did manage to force the second set to 4-4 having been 3-1 down.
Romania's Simona Halep, who beat Andrea Petkovic 7-6 (7/4) 6-3, stands between Williams and a rare quarter-final appearance. The American has barely registered her presence on the WTA Tour in the last 12 months due to injury.
Second seed Agnieska Radwanska's bid for a third final appearance in as many years continues.
The 2011 winner, who lost her title to Nadia Petrova last season, was pushed all the way to a first set tie-break by Canada's Aleksandra Wozniak but ultimately cruised to a 7-6 (7/5) 6-0 win.
Poland's world number four will next face Dominika Cibulkova, who beat Casey Dellacqua 7-5 6-3, but the competition is over for third seed Sara Errani.
The Italian lost 6-4 6-4 to Svetlana Kuznetsova and missed the chance to face Sorana Cirstea in the next round following the Romanian's win over Misaki Doi.
Ana Ivanovic will meet fifth seed Angelique Kerber after beating Elina Svitolina 6-3 6-0 and Madison Keys takes aim at Petra Kvitova having ousted Shuai Peng 7-5 6-2.
Denmark's Caroline Wozniacki will face Magdalena Rybarikova after the title hopefuls secured respective wins over Flavia Pennetta and Kirsten Flipkens.
Serbian sixth seed Jelena Jankovic meets Eugenie Bouchard - the Canadian teenager edging a hard-fought battle with cross-border rival Sloane Stephens 5-7 7-6 (9/7) 6-3.
Elsewhere, Samantha Stosur beat Kimiko Date-Krumm to book a face-off with Lucie Safarova.