However, despite a serious of controversial incidents Kyrgios' reputation is developing among tennis fans as being something a breath of fresh air in a sport considered by some to be overly-straight and officious.
After the match, Kyrgios said: 'It's awesome.
"I've had people behind me, backing me and never lost faith in me, even though I lost it in myself".
Roland Garros victor Ashleigh Barty is still number one ahead of Naomi Osaka as the players head to Montreal where a lot of points are at stake.
The Australian, the World No. 52 tennis player who was World No. 13 in October 2016, has been criticised for his verbal abuse of officials, unsportsmanlike behaviour and been accused of "tanking" - deliberating losing.
"I know how well Nick can play when he wants to play".
With his victory, Kyrgios will be seeded at the US Open later this month, and speaking like a man who has turned the page on a career that has under-delivered on its promise, he added: "This is only the beginning". From his underarm serves to getting advice from the crowd, he is simply box office but perhaps the time has come for him to mature into the Grand Slam victor we know he can be. This week means a lot.
"It's probably one of the best tournament weeks of my life", Kyrgios said after the match. On match point, Kyrgios revived a bit he's been doing this week, going to "consult" a spectator before uncorking a serve.
"This final I just felt like I was ready".
Elsewhere in Washington, 15-year-old tennis sensation Cori "Coco" Gauff clinched her first WTA title over the weekend.
Kyrgios eventually tied the second set at 6-6 and claimed the victory, his second of the year, in another tiebreak.
"I got a little emotional".
"I believe we need people like him in the game otherwise things become too serious".
"Every loss, there's something I learn from that, so I learned something about myself", Gauff said after her match.
"It's only the beginning and it showed this week by winning this tournament", he said.
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