We have our first huge upset at the 2014 Australian Open, as No. 14 seed Ana Ivanovic bested No. 1 seed and favorite to win the women's bracket, Serena Williams. Ivanovic fell in the first set but stormed back to handily take both the second and third sets, winning 4-6, 6-3, 6-3. She constantly fought back on tough points and Williams wasn't able to keep up.
Ivanovic had a match point up 5-2, but Williams fought it off to keep herself in the match, holding serve to force Ivanovic to serve for the match. Unfortunately for Williams, Ivanovic shut her out in the next game, serving up an ace on the final point to seal the victory.
Ivanovic hadn't taken a single set from Williams in four meetings, but this isn't exactly surprising given her high level of play of late. She won her warmup tournament in New Zealand and downed Samantha Stosur in her previous match here at the Australian Open.
This is the second straight year in which Williams has disappointed at the Australian Open. Last year, she fell to Sloane Stephens in the quarterfinals. This year, she's out a round earlier. It wasn't Ivanovic's most-important win of her career by any means -- she took the French Open title back in 2008, so she's been at this level before. Still, it might be the biggest upset of her career.
No. 9 seed Angelique Kerber fell in a minor upset to Flavia Pennetta, the tournament's No. 28 seed. It's not a huge upset because Pennetta is well-respected, but Kerber was the favorite in this one. Regardless, Pennetta took a close one in three sets, 6-1, 4-6, 7-5.
No. 4 seed Na Li cruised to victory in her match, however. Li took down No. 22 seed Ekaerina Makarova, 6-2, 6-0. Makarova had been playing well, eliminating Venus Williams to start the tournament, but Li is playing some of her best tennis at the moment. It was an easy win for Li.
Now, Li will face Pennetta in the quarterfinals.
There's still plenty of matches in progress on the day, with Novak Djokovic and the men's singles bracket's first half of round four before the day is done.