Williams, the top seed and title holder, will face another Russian player Margarita Gasparyan, who defeated Kazakh Yulia Putintseva 6-3 and 6-4 in 91 minutes.

Jo Konta was labelled "ruthless" by her injured opponent as she became the first British woman to reach the fourth round of the Australian Open since 1987.

She is already provisionally inside the world's top 40, but Allertova will also be buoyed by wins over Bethanie Mattek-Sands and Sabine Lisicki in reaching this juncture.

"It just feels like I'm competing to the best of my ability and that's all I can ask for". Sharapova left the court after she lost the second-set tiebreak but after she came back refreshed and revitalised, she raced to victory to set up a clash with Switzerland's Belinda Bencic. "I thought I played pretty well in the other matches, though - my first match I thought I gave a great effort, and my second match, under the circumstances, I thought I played pretty well, I thought".

Konta made her first major breakthrough at last year's US Open when she beat Spain's Garbine Muguruza in the longest women's match in history at Flushing Meadows. "I was just very happy that I was able to take advantage of certain key points in the match and to keep my momentum going". Her first serve was firing at 72 per cent and she forced 12 break points and faced none.

"I am exhausted and sad, because without this injury I thought I had a chance".

Gavrilova savoured the moment after marching into the fourth round, saying on court: "I'm just really excited and want to hug the whole stadium!" She meets qualifier Naomi Osaka having dropped only three games so far in completing a 6-0 6-0 win over Alison Van Uytvanck in the first round and a 6-1 6-2 success against Danka Kovinic in the second.

The seventh-seeded Nishikori saved eight of 11 break points, including three at 5-3 in the third set when he was serving for a two-sets-to-one lead.

The Sydney-born Eastbourne resident is cultivating a local following here, where she played as a junior. "Not something I ever aimed for or looked for, but when it happens, it's very special", he added.

Makarova, 27, reached the semi-finals at last year's Australian Open and the quarter-finals in 2012 and 2013, but Konta is in the form of her life. "So I thought, it would be really fun to play in one", she said. "I can say that was probably the best win of my career".

"Yeah, I am very emotional". Being a British tennis player, it would be wise not to get overly carried away.