The match at the Rod Laver arena finished 6-3 3-6 4-6 7-5 6-2 and saw some top quality play from both men.
Speaking after the victory Roddick said "I was lucky to get out of that, sometimes if you fight and stick around you give yourself a shot."
"When Fernando gets hot you know a lot of the match is out of your control... if i didn't have my first serve and winning points on that i'd be booking plane tickets home."
After dropping the opening set Gonzalez started playing some fantastic cavalier tennis to take a two sets to one lead, but it was the fourth set that decided the match.
With opportunities to break early on not taken momentum began to swing away from the Chilean.
Utilising his powerful serve and aggressive forehand return Roddick generated six break points during the set before finally clinching it 7-5 after a successful Hawk eye challenge.
Roddick faces Marin Cilic who also took five sets to upset world no.4 Juan Martin Del Potro in the next round.