Meet Nick Kyrgios the tennis player

Nishikori, Kyrgios advance in Miami (5:04)

Kei Nishikori and Nick Kyrigios advance to the semifinals at the Miami Open. (5:04)

MIAMI -- Nick Kyrgios is just 20 years old, but he sounded like a weary veteran following his upset of Milos Raonic at the Miami Open on Thursday night.

Kyrgios, as notorious as he is talented, remarked after the match: "These last few years on the tour, they've been a bit of a roller-coaster. But I've learned a lot."

Every facet of that accumulated knowledge was on full display in the lanky Aussie's 6-4, 7-6 (4) win. Kyrgios kept his mercurial temper in check, allowing himself just the occasional, bitter soliloquy after a botched shot, and he yakked with only one targeted supporter.

Kyrgios served rockets and returned bullets. He belted forehands and whaled on backhands. As a competitor, he was a razor. By comparison, Raonic -- no slouch in the power department himself -- was a butter knife.

The statistics tell the tale of a young pro flinty beyond his years. The combatants put up nearly identical numbers in many critical departments. (Kyrgios had 26 winners, one more than Raonic; they each made 26 unforced errors and each one won 78 percent of his first-serve points.)

These are both big men. At 6-foot-5, Raonic, the No. 12 seed here, is an inch taller and certainly heftier than the whipped lean Kyrgios. At 25, Raonic has almost five years on the No. 24 Kyrgios. Yet the Canadian seemed the younger, less assured man. He was hesitant where Kyrgios was fearless. Raonic seemed to play within himself, while Kyrgios fought with abandon. When Raonic went wobbly, Kyrgios stepped up. When Raonic misplaced his serve, Kyrgios found his swerve and swagger.

"I thought I competed well today," Kyrgios said.

Raonic expounded on his opponent's sentiments.

"He came up with the big shots at important moments," Raonic said. "He had more life and energy."

Kyrgios has won just one title in his budding career (and that was just weeks ago, in Marseilles). He spent his first few years on the tour trying on roles, as teenagers are apt to do, and made some unwise choices. He's an emotional young man. It's unlikely that he'll ever evolve into a tight-lipped, ramrod straight Rod Laver.

By his own reckoning, some of those outbursts and emotional explosions that landed Kyrgios in trouble were the byproduct of a perfectionism that has plagued many great, emotionally volatile players.

Those who wondered if he'll ever change and take tennis seriously may be surprised to hear that the path to a more settled disposition lies in the other direction.

"If anything, I'm not taking it [tennis] as seriously," Kyrgios said. "At the end of the day, it's just tennis. I'm just going out there and trying to play."

It's working.

Every elite player in tennis has a niche or role. Roger Federer is the guy with the "beautiful game." Rafael Nadal is the ultimate warrior. Novak Djokovic is the stern, stony-visaged punisher. Kyrgios, should he continue his mercurial rise, is on track to be nothing less than the most electric pro in the game.

The player Kyrgios most resembles is Gael Monfils. Both men are superb athletes -- emotional, communicative and natural showmen. But there's a critical difference. Monfils appears to have a soft center. Kygrios, by contrast, seems to be have a steel core and a serrated, sharp edge.

Monfils clearly wants to please the crowd. Sometimes he appears to put that mission ahead of winning. Kyrgios is emotional, so naturally the crowd is drawn to him. But he doesn't give the impression that he's drawn to it. He's out there by himself, for himself. He doesn't want to be loved, at least not if he has to love back. He wants to win.

Those are qualities that will take him far in a me-first game.

"He has one of the bigger upsides in the [under-25] group," Raonic said.

Kyrgios is in his first Masters 1000 semifinals. If his form holds up, he could leapfrog some excellent players young and old to make a major breakthrough. He has the talent. He has the disposition. He's already been to two Grand Slam quarterfinals. Is he the fresh face destined to do what only 31-year-old Stan Wawrinka has accomplished -- break the stranglehold the big four have on the men's game?

"There's opportunity everywhere," Kyrgios said. "Dominic Thiem is making a run. [David] Goffin is playing great. There's so many out there trying to make a breakthrough. I don't really see myself as that guy."

Not yet, perhaps, but it must feel great for him to be off the roller coaster with his feet planted firmly on the ground.