Inspired by hero Lleyton Hewitt, Australian teenager Alex De Minaur fought out a gruelling five-set win over Austrian journeyman Gerald Melzer in the first round of the Australian Open.

The Australian Davis Cup captain watched from the stands as the 17-year-old fought back from a match point down to record a 5-7 6-3 2-6 7-6 (7-2) 6-1 triumph on his grand slam debut.

“Words can’t describe how I’m feeling right now … definitely the happiest moment of my life,” De Minaur said.

“I never felt such an unbelievable experience with a crowd. They were loud the whole match. I’m pretty sure they got me through that match.

“I just wanted to put on a good show, fight for every point. At the end of the day it went my way.

“I couldn’t be happier.”

As Hewitt did so many times at Melbourne Park, De Minaur fought back from the brink, saving a match point in the fourth set and working tirelessly throughout.

The teenager broke Melzer seven times and hit 50 winners in a marathon encounter that lasted three hours and 43 minutes.

A beaming De Minaur paid tribute to Hewitt.

“It’s unbelievable to have him in my corner there, unbelievable support, he’s been really helping me out a lot,” he said.

“Obviously I watched a lot of his matches. That (fight) is something I admire from him. I was really happy that I could do that today.

“Coming through with my first five-set win. I wouldn’t have rather done it anywhere else.”

The Spain-based youngster faces a tough encounter against big-serving American No.31 seed Sam Querrey in the second round.

“I’ll probably just try to get the return back and then we’ll see what happens,” De Minaur said.

“But I’m going to try and focus and play my game. We’ll see where that takes me.

“I can’t wait to get back on court and hopefully good things will come.”