Kyrgios, only 18 years old but already a statuesque figure at 193 centimetres, describes his background as half Greek and half Malaysian but he hails from Canberra and counts former Wimbledon champion Pat Cash as a friend and mentor.
A late wildcard entry at Roland Garros, he is still intending to play in the junior event and changes with the other tyros at a different end of the sprawling grounds.
Firing down a string of aces in their first-round encounter, he won 7-6 7-6 7-6 against Czech Stepanek, 34, who is one of the tour's most experienced campaigners and ranked 210 places above him.
"I had a lot of nervous energy in the third set," Kyrgios told reporters. "My fingers started mini-cramping I guess you could say - I think I'll feel better, more comfortable in my next round.
"When I woke up I was pretty nervous (but) when I got out there I started playing some really good tennis."
The youngster now faces a even sterner test in the shape of Croatia's 10th seed Marin Cilic who hit 35 winners as he ousted German Philipp Petzschner 6-1 6-2 6-3.
"I hit with him a couple of days ago before the main draw," Kyrgios added. "He's an unbelievable player.
"He's got to where he is playing world-class tennis. I'll focus on what I have to do the next couple of days."
Asked whether he planned to alter his routine and change with the senior players, he replied: "I'm still using the locker room at Suzanne (Lenglen Court) so I don't think that will change any time soon."
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