Was Nick Kyrgios' Davis Cup performance his turning point?

Nick Kyrgios is approaching a long-predicted and often-deferred breakout at an accelerated pace, ticking off one box after another as the year goes on.

He completed his latest task Sunday, leading Australia to a 3-2 win over a U.S. Davis Cup team led by Jack Sock. Kyrgios won both his singles matches. He clinched for the Aussies by overpowering Sam Querrey 7-6 (5), 6-3, 6-4 in the fourth rubber.

Sock, ranked one tick above Kyrgios by the ATP at No. 15, was the U.S. No. 1 player. But when the U.S. fell behind 2-0 on the first day of play, captain Jim Courier decided to use his top singles player in the next day's must-win doubles.

Sock and Steve Johnson got the job done, but it took five long sets. So Courier pulled Sock and substituted Querrey, whose ATP ranking is No. 25, for the critical fourth match. It wasn't just that Querrey had fresh legs. He was also one of the few players who has beaten Kyrgios recently, accomplishing that en route to title week in Acapulco last month.

Because of his behavior, Kyrgios has never felt the full embrace of the Australian public. When you mixed his dodgy reputation, Querrey's recent win and the pressure of the Brisbane home crowd's expectations, the result was a potential meltdown. But Kyrgios took a deep breath, put his shoulder to the wheel and quietly pushed the load over the finish line.

He may be ranked No. 16, but Kyrgios has been playing exceptional tennis for a few months. Just as important, he's been expressive and entertaining, but not at the expense of effectiveness.

"It's all in his hands," Courier told reporters after the tie, talking about what the 21-year-old Aussie's performance might forecast for his future. "Concentrated, focused and resilient -- he can and should be top-five by the end of the year."

Kyrgios' own words and actions during the tie suggested that he's coming to terms with the demands of his profession. For the better part of the past three years, he claimed to not care much for the game he plays so well. To many, it seemed a reaction to the pressure he felt as the presumed Next Big Thing. But his words and actions also revealed his immaturity. His showmanship could bring a big smile to your face; his vulgarity could make you cringe.

It all came to a nadir with an ugly tanking controversy at Shanghai last fall. Perhaps, significantly, that meltdown and subsequent suspension came right on the heels of the best result of Kyrgios' career, a title-winning run at the Japan Open.

Maybe the ensuing disaster was self-sabotage. Maybe it was driven merely by petulance or a lack of discipline. Or the inability to overcome fatigue. Whatever the case, the incident ended Kyrgios' year and landed him in counseling.

But what he's doing now has the look of a turning point.

"I haven't been going back to the hotel hating the game or trying to just get through every day," Kyrgios told reporters after the Miami Open last week. "I'm trying to get better every day, and it's a massive difference. I just feel like I'm becoming a bit more of a professional."

This was a major statement from a player who has been loath to speak freely and openly with the media. If the sea change is permanent, it's surprising but also fitting that it came to a head at a Davis Cup tie. Because of his independence, Kyrgios was persona non grata to the Australian tennis establishment for much of his young career. But one person who never gave up on him was Davis Cup captain and true-blue Aussie, Lleyton Hewitt.

The captain, who has the greatest Davis Cup record of any Australian, knew from his own experience that the event can do as much for a player as a player does for it. Players crave respect and acceptance, and distinguished Davis Cup service is a surefire way to earn it.

Hewitt himself was reviled by many as a pugnacious punk when he burst onto the scene at the start of the millennium. His Davis Cup heroics played a major role in his rehabilitation.

"There is no greater honor than wearing the green and gold," Hewitt reiterated after the tie. "I couldn't be prouder of my boys. They've put so much hard work and effort into this campaign. They did absolutely everything we asked of them."

Kyrgios said he'd been prepping for this tie since January, when he was booed off the court after his heartbreaking, five-set second-round loss to Andreas Seppi in the Australian Open. Kyrgios was surprised by the reaction, because he had given his best effort. He vowed to himself that he would win the crowd over on this occasion, a battle between the two historic Davis Cup titans.

"[The team] always had one eye on it -- or at least I did," Kyrgios said. "I was trying to play well over the last couple months to try and set a good example and try and just get myself better and ready to compete."

It's an interesting admission. The Davis Cup tie helped explain the brilliant level that Kyrgios often achieved in those recent weeks when he beat Novak Djokovic twice in various events and came within a whisker of halting Roger Federer's winning streak in a three-set tiebreaker loss at the Miami Open. All of this surely helped account for the command and self-control Kyrgios showed during the Davis Cup tie.

Kyrgios admitted that he got the Davis Cup heebie-jeebies in the third set against Querrey, falling behind 4-1 before mounting a furious comeback driven by inventive shot-making that his American rival couldn't match.

"Obviously, a lot of emotions close to the finish line," Kyrgios said. "But with Lleyton on the side telling me to compete for every point and -- obviously -- the crowd, it's easy to get up out there."