Dwarfed by tennis's giants, Jordan Thompson is banking on his mental steel as he enters the second week of grand slam for the first time.
Chuffed but not content with his charge to the fourth round, Thompson can gatecrash the US Open quarter-finals with victory over Croatian Borna Coric on Monday.
He's an underdog against the 27th seed and knows he can't match it for height and reach with the sport's big boppers, but the 182cm high Thompson is backing his focus and resolve to give him a fighting chance of extending his breakout run.
"Just with the way I play, there shouldn't be any lapses. I've got to be relentless with my concentration," Thompson said.
"Compared to the ATP Tour, I'm pretty small so I'm not going to blast people off the court.
"So concentration can be an asset of mine so I've been trying really hard to focus on that."
What he lacks in height, Thompson more than makes up with in conditioning.
"My physicality has been really good as well," the Davis Cup star said after winning eight of the last eight games of his third-round success against Mikhail Kukushkin.
Thompson hasn't played Coric since losing a three-setter to the Croat in Thailand seven years ago.
Coric is in fine form, taking out Greek fourth seed Stefanos Tsitsipas en route to the last 16.
But it took him five sets and more than four and a half hours to do so.
"He's a quality player," Thompson said.
"It's going to be a tough next match, a tough test.
"But the fourth round, I feel like I've got nothing to lose. It's another opportunity that I'm just happy to be there and I'll give it my all as I always do."
AUSSIES IN ACTION ON DAY SEVEN OF THE US OPEN ON MONDAY AEST
Men's singles, fourth round:
Jordan Thompson v 27-Borna Coric (CRO) - not before 7am AEST