Day 4 at the Australian Open

Maria Sharapova was tested to the limit as her Italian opponent Karin Knapp wasn't going to let the third seed breeze into the third round.

Sharapova [3] beat Knapp 6-3 4-6 10-8
In a match that lasted three hours and 28 minutes, and in temperatures that peaked at 42.4C, it was Sharapova that eventually prevailed.

The set that decided the match alone lasted one hour 55 minutes, the Italian was determined to not make it easy for the third seed.

After failing to capitalise on match points at 5-4, the Russian eventually broke to lead 9-8 having been two points from defeat a game earlier.

Azarenka [2] beat Z-Strycova 6-1 6-4
Defending champion Victoria Azarenka pulled through a tough second set to defeat Barbora Zahlavova Strycova to advance to the third round.

The winner in 2012 and 2013 moved 3-1 up in the second set after breezing through the opening set, but was broken twice as her Czech opponent levelled at 4-4.

However, Azarenka broke again and then served out the match.

Paire [27] beat Kyrgios 6-7 6-7 6-4 6-2 6-2
Australian teenager Nick Kyrgios showed signs of future stardom as he took the first two sets in front of his home crowd. At 1:40am the crowd stayed with the match to find out its conclusion.

However, the young Aussie became tired and suffered from cramp in the closing stages as the Frenchman booked his place in the third round of the Australian Open.

Other results from day 4:
Cornet [25] beat Giorgi 6-3 4-6 6-4
Stephens [13] beat Tomljanovic 3-6 6-2 7-5
Monfils [25] beat Sock 7-6 7-5 6-2
Tsonga [10] beat Bellucci 7-6 6-4 6-4
Radwanska [5] beat Govortsova 6-0 7-5