Australian wild card Alex Bolt put up a valiant effort, but the world No. 5 seed Dominic Thiem is through to the third round after an epic 6-2, 5-7, 6-7 (5-7), 6-1, 6-2 victory.
Bolt looked down and out at 3-5 in the second, but he valiantly fought back with four games in a row to take it by two clear games.
Thiem was forced into a dramatic tie-break in the third and saved three set points before the world number 140 slammed down an ace to seal it 7-6 (5).
But Thiem regained his composure and won 11 of the next 14 games to cruise through the fourth and fifth sets.
Thiem will play either Kevin Anderson or Taylor Fritz in the third round.
"It was a tough match. Alex played great with great support, it was great fun to play for him and for me to play in such an atmosphere.
"I think it was my first win on Melbourne Arena so I'm very happy.
"I like playing in a great atmosphere and the crowd was fair. It's way nicer to play in front of a full crowd who is against you than an empty stadium."
