World No.35 Yulia Putintseva stormed back from a set deficit to stun World No.1 Iga Swiatek while No.21 seed Elina Svitolina of Ukraine charged past two-time finalist Ons Jabeur in the third round of the women's singles action at the Wimbledon on Saturday.
Elina Svitolina becomes the sixth player among the top 10 seeds to be ousted from this year's Australian Open before the pre-quarters.
Their head-to-head coming into the match was equally split, with four wins each in eight meetings, and the Romanian having won their two most recent clashes at Wimbledon and in Doha.
Elina Svitolina dominated the second set from the word go and broke Karolina Pliskova in the very first game to eventually win first match of WTA Finals.
Williams will now face No 5 Elina Svitolina of Ukraine on Thursday to remain on course of her 24th Grand Slam.
Andreescu, 19, who clinched her second professional title at the Women's Tennis Association Premier 5 event in Toronto, needed just one hour and 55 minutes to reach her first Grand Slam quarterfinals.
On Sunday, Williams entered the US Open quarters for the 16th time in her career with a straight-set win over Petra Martic of Croatia at an electric Arthur Ashe Stadium.
The former world no. 1 dominated from the very beginning, punching a barrage of winners to storm to 4-0 in the opening set in just 19 minutes.
A blossoming romance between new tennis power couple Elina Svitolina and Gael Monfils has fans baying for more, with the pair obliging by setting up a joint Instagram account.
Japanese US Open champion Naomi Osaka and sixth seed Elina Svitolina survived big scares but displayed fighting qualities to pull back from the brink at the Australian Open on Saturday.
