"Absolutely fantastic," said Neale Fraser, the 1960 Wimbledon champion. "Probably the best result from an Australian player in 20 or 30 years. Maybe 40 years."
Three-time Wimbledon champion John Newcombe has been working the Australian teenager's matches for television Down Under.
"He's got better with every match," Newcombe said. "Yesterday he got better with every set. He just went from strength to strength. At the end of the third set, you're thinking, 'What is going to happen now?' "
After the giddy feeling of the match began to fade, that was the real question. Could Kyrgios possibly avoid the inevitable letdown that seemingly must follow the greatest victory of a young lifetime?
"I don't understand letdowns," four-time Wimbledon champion Rod Laver said. "His confidence is good. Maybe if he has to hit it nice and slow, get it in the court, it might be tough. If he bombs it, they all go in."
That's how it went for about a set in the 19-year-old's quarterfinal against No. 8 seed Milos Raonic. And then he slammed into the restraining wall that many saw coming after an unconscious week here. He couldn't manage to save nine match points, as he did in the second round against Richard Gasquet, or execute the no-look, between-the-legs half-volley winner that froze Nadal.
Raonic prevailed 6-7 (4), 6-2, 6-4, 7-6 (4), and now gets the daunting task of facing seven-time Wimbledon champion Roger Federer in his first Grand Slam semifinal.
"It hasn't really sunk in yet," Raonic said minutes later. "Yeah, it's another step forward. My goal is to be the best player in the world, and this is one of the steps I have to take.
"To do it on this stage makes it so much more special."
He hit 39 more aces, giving him a tournament-high 147 in five matches here.
Kyrgios, who received a wild card into the main draw after winning the Nottingham Challenger a few weeks ago, was bidding to become only the fourth card to reach a Grand Slam semifinal. He would have been the youngest Wimbledon semifinalist since 18-year-old Goran Ivanisevic did it in 1990. He also invoked comparisons to 17-year-old Boris Becker, who crashed the tennis establishment party and won the title in 1985.
That's the wild, out-of-the-blue trajectory Kyrgios was tracing.
Nineteen-year-olds are famously full of energy, but entering the match, Kyrgios had already spent nearly four more hours on court -- and made a significant emotional investment, too.
Nevertheless, the Aussie smacked his way into a first-set tiebreaker and, after throwing his racket into the turf, seemed to relax. His last two serves were unreturnable, and now he had won three straight sets against top-10 players.
In the second set, he made a shot almost as improbable as his between-the-legs winner against Nadal. Kyrgios ran all the way across the court and, at full speed, picked a forehand inches off the ground and hit it cross-court, barely over the net. The angle was so extreme that Raonic didn't really move for the ball.
But then, for the first time in the tournament, Kyrgios seemed to hit a wall. His serve that was broken only once in the Nadal match was broken twice in a span of 15 minutes -- and, so, Raonic was even. In time, the third set was his as well. The fourth soon followed.
Early in the tournament, when Grigor Dimitrov was asked about the Big Four, he said there soon would be some breakthroughs by young players.
"As I said, it was around the corner," Dimitrov said after defeating defending champion Andy Murray. "I didn't know it was that around the corner. I mean, what can I say? We want to win. I think the younger guys, we want to come on that stage. We strive for this. I think we're thirsty for that. We want to prove ourselves."
Last year, Jerzy Janowicz, a 22-year-old from Poland, raced into the semifinals here, but hasn't really been heard from since. But you get the idea that Kyrgios, because of his age and raw talent, will have more staying power. Raonic is already in position to win this major tournament.
"I've got to serve well," he said of his Friday match against Federer. "It's going to be a great challenge. I really wanted to put myself in this position.
"I'll compete hard and we'll see what happens."
Bryan brothers advance
They lost the first set to the No. 9-seeded team of Julian Knowle and Marcelo Melo before rallying to win 3-6, 7-6 (6), 6-4, 6-4. The defending champions next play the No. 12 team of Michael Llodra and Nicolas Mahut, who beat No. 4 Julien Benneteau and Edouard Roger-Vasselin 6-4, 6-4, 5-7, 6-4.
There were no Americans through to the fourth round in either the men's or women's singles main draws, but the U.S. juniors are having a good tournament. Francis Tiafoe, the No. 2-ranked junior boy in the world, won his second-round match 7-6 (4), 6-3 over Yunseong Chung of South Korea. No. 6-seeded Stefan Kozlov handled Spain's Pedro Martinez Portero 6-0, 6-2. No. 11 seed Michael Mmoh won 6-3, 6-2 over Jan Zielinski of Poland, and Taylor Harry Fritz beat No. 14 seed Marcelo Zormann of Brazil 6-4, 7-6 (3) . . . Two U.S. girls also advanced in singles: No. 3 seed Tornado Alicia Black won 6-2, 6-4 over Rebecca Sramkova of Slovakia, and Michaela Gordon defeated Isabelle Wallace of Great Britain 6-2, 5-7, 8-6 in a match that ran 2 hours, 39 minutes.