With his father banned from the US Open and memories burning of an early surrender in a second-round exit last year, Australia's Bernard Tomic ground out a five-set victory on Monday.

Tomic, No 52 in the world, rallied to outlast Spain's 75th-ranked Albert Ramos 6-3, 3-6, 4-6, 7-6 (1), 6-3 and said he felt he had proven a point with a courageous fightback.

One year after headlines dubbed him "Tomic the Tank Engine" after he lamely withered through the final games of a second-round loss to Andy Roddick, the 20-year-old was on his game, not going home.

"To turn any match around like this where I think I was probably one or two points away from being out of the tournament, being able to turn that around and find something inside to win this match, was very good for me, and I take confidence into my next round," Tomic said.

He will next face 179th-ranked British qualifier Daniel Evans, who upset Japanese 11th seed Kei Nishikori in the first day of play on the Flushing Meadows hard courts.

Tomic's father and coach, John Tomic, has been banned from ATP and Grand Slam events after being accused of assaulting Thomas Drouet, who had been his son's practice partner, in Madrid on May 4.

It's a charge the elder Tomic has denied and the matter remains before a Spanish court.

"I'm managing now," Tomic said. "It's still difficult, but what can I do? I'm trying to play as best as I can.

" The main thing now for me is just to keep improving. That's where my mindset is at."

That means becoming more independent of his father.

"I'm not looking where my dad is," Tomic said. "Of course he is still on my side ... but I'm trying to find myself deep down inside and become the best player I can be."

With fitness coach Ivan Dimitrijevic in the player's box, Tomic has somewhere to turn when times get tough.

"I felt very good to come back from that match," Tomic said. "He should have got the better of me, but I found something in the end to turn it around."