What do you do when the unbackable favourite is beaten?
Do you celebrate? Dare to dream? All of the above? If you're Ana Ivanovic, Li Na, Flavia Pennetta or Eugenie Bouchard, the path to the final of Australian Open 2014 has just got that little bit easier, and it's thanks to Ivanovic.
The former world No.1 pulled off the upset of the tournament on Sunday with her come-from-behind 4-6 6-3 6-3 victory over Serena Williams during the day session at Rod Laver Arena.
While Williams went to great lengths to pay tribute to Ivanovic and not make excuses for her loss, her coach, Patrick Mouratoglou, revealed that the top seed was struggling with a back complaint. A problem so bad Williams was unable to carry her own bag onto court.
"I don't want to blame anything. I feel like Ana deserves all the credit. I feel she played unbelievable today. I think she went for her shots," said Williams.
"It's not like I gave her the match. I tried to fight the best I could today."
Ivanovic's next challenge, admittedly slightly less daunting than Williams, is 30th-seeded Canadian Bouchard who knocked out Casey Dellacqua in three sets, 6-7(5) 6-2 6-0.
Joining Ivanovic and Bouchard in the quarterfinals were dual finalist Li Na and surprise-packet Italian Flavia Pennetta, whose unlikely streak continues.
Li's defeat of serial Australian Open upset artist Ekaterina Makarova was one of the quickest matches on Sunday. The 6-2 6-0 routing of the Russian 22nd seed took just 59 minutes.
Li will take on Pennetta, who fought off German ninth seed Angelique Kerber in three sets, 6-1 4-6 7-5 to make it through to her first-ever Australian Open quarterfinal.
In men's action on Sunday, Novak Djokovic's tilt at a fourth-straight title – and fifth overall – continues to gather steam. Fabio Fognini provided little resistance in the face of the Serbian juggernaut, the closest Fognini came to inflicting any damage on his opponent was when he half-heartedly threw his racquet at the second seed.
Tennis's invisible man, the always hard-working David Ferrer, had a slow start against rangy German Florian Mayer but improved the longer the match lasted, winning 6-7(5) 7-5 6-2 6-1.
Next up for Ferrer in the quarterfinals is seventh seed Tomas Berdych, who was in imposing form as he brushed aside 19th seed Kevin Anderson. Big Berd is yet to drop a set or his serve this week and is now through to his fourth-straight quarterfinal here.
The tall Czech will be looking to make it through to his maiden Australian Open semifinal, but Ferrer is a difficult prospect.
Unbackable favourite Williams may already be just a distant memory, but this is no time for celebration just yet. Now the real business of winning a major begins.
What did you say?
QUESTION: Patrick [Mouratoglou, coach] said that you blocked your back and then you blocked your neck.
SERENA WILLIAMS: So he's the one that's snitching?
It’ll be a long drive home for …
Serena Williams. The world No.1 has had a tough run with injury at the Australian Open in recent times. Hopefully for her sake and her fans, she will be fully fit when she returns to Melbourne in 2015.