Lleyton Hewitt remained on course to win his home Grand Slam after battling back to beat James Blake 4-6 7-6 (8-6) 6-0 6-3 in the second round.
In an enthralling match, Blake took the opening set and had a point to take a two-set lead in the tiebreak.
But screamed on by a patriotic crowd, Hewitt produced his best tennis of the match to see off the danger.
At set point, Blake scraped his hand in a desperate dive and his game then fell apart, losing 12 of the next 15 games.
Hewitt could face Rafael Nadal in the fourth round after the Spaniard fought back from match point down to beat 15th seed Mikhail Youzhny.
The Spanish teenager was facing defeat with Youzhny 5-4 up in the fourth set and with advantage.
But the Russian, who was struggling with a thigh injury, missed a backhand volley and Nadal went on to triumph 6-1 4-6 4-6 7-5 6-3.
The 17-year-old now faces American surprise package Bobby Reynolds, who upset 17th seed Andrei Pavel. Reynolds, 24, is playing at the Australian Open for the first time and had won only one Grand Slam match in his career before arriving in Melbourne.
However, he swept past Pavel 7-6 (8-6) 6-2 6-2.
Sebastian Grosjean became the highest seed to go out of the men's event when he lost to fellow Frenchman Jean-Rene Lisnard.
The 14th seed had a two-set lead but fell to a 1-6 4-6 6-3 6-4 6-3 loss.
It was another unhappy Australian Open exit for Grosjean, who lost from a similar position to compatriot Arnaud Clement in the 2001 semi-finals.
Olympic champion Nicolas Massu pulled out of his second-round match with an injury.
The Chilean was trailing Germany's Phillip Kohlschreiber 0-6 0-2 when he withdrew with an ankle injury.
The same problem caused Massu to pull out of the Kooyong exhibition event before the Australian Open began.
The 18th seed also received treatment on his back during his first-round win over Anthony Dupuis, which took nearly four hours.