
Australian Open Day Four —
Serena Williams was pumped up after beating former world No. 2 Vera Zvonareva in the second round. Williams saved three set points in the first.

Australian Open Day Four —
The second set, though, was one-way traffic. Williams served well and eventually cruised 7-5 6-0.

Australian Open Day Four —
Williams' older sister, Venus, also advanced. She crushed fellow American Lauren Davis. Can Williams end her five-year quarterfinal drought at majors?

Australian Open Day Four —
Thursday's top matchup, on paper, pitted Victoria Azarenka, right, against Caroline Wozniacki. Azarenka was the winner, 6-4 6-2.

Australian Open Day Four —
The pals shared a hug at the net when it was over. Azarenka could meet Serena Williams in the quarterfinals.

Australian Open Day Four —
Staying hydrated was key on a day where temperatures hit almost 36 degrees Celsius. Novak Djokovic didn't linger on court, quickly disposing Andrey Kuznetsov.

Australian Open Day Four —
Despite the hot temperatures, Djokovic stayed on court to sign autographs. He's bidding for a fifth Australian Open title.

Australian Open Day Four —
Kei Nishikori said he felt dizzy because of the heat. But the U.S. Open finalist still defeated Ivan Dodig in four sets.

Australian Open Day Four —
Feliciano Lopez admits he's lucky to still be in the tournament. The 12th seed -- for the second straight round -- saved a match point to advance. On Thursday, Lopez's opponent, Adrian Mannarino, retired in the fourth set.

Australian Open Day Four —
There will be no fairy-tale ending for Aussie Lleyton Hewitt in Melbourne. The 33-year-old, seen here, lost in five sets to fellow 33-year-old Benjamin Becker.