Sydney, January 9: Angelique Kerber continued her positive start to 2018 as the former world number one beat second seed Venus Williams at the Sydney International.
Kerber endured a torrid 2017 that saw her slip out of the top-20, lose the German number one spot and exit all four grand slams before the quarter-finals.
But a new year has given Kerber a renewed vigour and that was evident on a rain-affected day five in Sydney as she came from behind to beat Williams 5-7, 6-3, 6-1.
Rain delays meant the pair did not take to court until after 2100 local time and it took Kerber time to find her rhythm, but once she did Williams had no answer.
Kerber reeled off eight successive games to level the match and take a 5-0 lead in the decider, but she made hard work of finishing Williams off, needing a fifth match point to advance to the last eight.
.@AngeliqueKerber has done it!January 9, 2018
She is joined in the last eight by Dominika Cibulkova and Ashleigh Barty as they both won in straight sets against Elena Vesnina and Ellen Perez respectively.
Defending champion Johanna Konta made an unexpected early exit as Agnieszka Radwanska sent the fourth seed packing in a repeat of last year's final.
Radwanska broke Konta on six occasions on Ken Rosewall Arena and found 14 winners as she turned the tables on events 12 months ago, the Pole winning 6-3, 7-5 in one hour and 49 minutes.
Daria Gavrilova was on the brink of victory over Olivia Rogowska when the rain came, the world number 25 eventually returning to secure the one further game she needed to progress.
She will meet Sam Stosur after her win over Carina Witthoeft, while there was also a second-round triumph for Barbora Strycova.
Over in Tasmania, defending champion Elise Mertens cruised into the last eight of the Hobart International with a 6-4 6-4 win over Beatriz Haddad Maia.
She is joined in the quarter-finals by Donna Vekic, Mihaela Buzarnescu and Lesia Tsurenko – the fifth seed beating Yulia Putintseva in straight sets.
The first round was completed on Tuesday with both seeds in action losing, Irina-Camelia Begu beaten by qualifier Monica Niculescu and Katerina Siniakova eliminated by Alison Riske.