But, having already defied the expectations of the tennis world - and his own mother - by slaying the great Rafael Nadal, it seems there is little the Canberra teenager can not do.

Kyrgios admits he was unimpressed that his mother, Norlaila, thought Nadal would be too good for him on centre court in the world’s biggest tournament.

“It actually made me a bit angry,’’ he said, after achieving the wildly improbable in four intense sets on the famous centre court. “You would think he's in a whole 'nother level compared to me. I just believed in myself that I could create some opportunities. I took them under pressure today.’’

He took them, indeed, while appearing not to be feeling any pressure at all, and laughed that the best comeback might just be to text his non-believing mother “a smiley face”. Krygios said he never doubted he could beat the winner of 14 grand slams, played like it, and spoke afterwards like a young man for whom there is no turning back.

“Never did I think a week ago I was going to make the quarter-finals of Wimbledon in my first appearance,’’ he told a crowded interview room, where he described himself as a “normal kid” who travels with his X-box, named his victory jig “the juice wiggle’’, labelled his decision to opt for tennis over basketball as “the best choice of my life”, and reiterated his desire to fill Nadal’s place as world No.1.

Having considered abandoning the grass court season after a first-round Challenger loss in Nottingham last month, he admitted his achievement was yet to sink in, and expected the positive impact would be enormous.

“I'm going to draw so much confidence out of that no matter where I play now,’’ said the world No.144, who will meet Raonic on court No.1. “To have that under my belt, it's massive.

“I think I had to play a solid game that gave me the best shot: that's serving big and playing aggressive. I thought today my serve was something that got me over the line. It made me be able to put pressure on his serve as well. I think that was very important.’’

He admitted it would be a “tough ask” to recover in time to give his best against Raonic; to play consecutive best-of-five-set matches in just his fifth major tournament. Raonic, too, needed four sets to beat Kei Nishikori and become the first Canadian quarter-finalist at the All England Club in 102 years, but in far more low-key circumstances on court three.

“I'm going to do everything possible and see how my body responds tomorrow,’’ said Kyrgios. “If I come up short, I come up short. I'm going to give it my best shot, and whatever happens, happens. Miilos has probably got the best serve in the world. I'm just going to go out there and have fun again.’’

Whatever works, and however fearless he may appear in the clutch moments, that is apparently not the full story. “Definitely I'm scared. Like I just go through my routine and I just play aggressive. If they play too good on that point, then it's too good. But I'm going to go after it and give myself the best chance to win the point.

“I think on the big stage, it's something I thrive on, the atmosphere, the crowd. I just love it when at 5-3, I think it was in the fourth set, they erupted, the crowd. I just love that feeling. At that stage you just think about all the work you put in. You know if you believe in yourself. Especially with my serve, if I just go after it, hit the right spots, I'm going to have a pretty good shot to close out a match like that today.’’

Australia is breathing down his neck in its desire for its next champion, aware of the false dawn that was Bernard Tomic’s exhilarating run to the last eight in 2013, but that’s fine, too.

“I'm not feeling any pressure. I'm just feeling motivation to keep going and give my absolute all out there. No matter what happens, I'll be happy.’’

Kyrgios is guaranteed to rise from 144th to about 65th in the rankings, regardless. He does not expect to be given any rhythm by Raonic, who beat him 6-3, 7-6 (7-1), 6-3 on the Roland Garros clay, but does anticipate a swag of winners, and “a lot of walking from side to side from his serve’’.

Does his mum think he can win that one? “I I hope so.’’

And the tournament? The whole thing? “I hope so.’’