Kyrgios hints at girlfriend as motivating factor for recent run of success after Citi Open triumph

Australian tennis star Nick Kyrgios had to wait three years for his seventh ATP singles title, but he did it in style as he outclassed Yoshihito Nishioka 6-4 6-3 in the Citi Open Washington final.

The Cranberra native followed up his singles title with a victory in the doubles category, where he and Jack Sock defeated Ivan Dodig and Austin Krajicek 7-5 6-4.

Enjoying arguably his best-ever season, Kyrgios jumped 26 places in the singles rankings from 63 to 37, and would have been much higher on the list if the points at Wimbledon counted. The 27-year-old reached his first Grand Slam final this year in London, where he lost to Novak Djokovic in four sets.

Boasting one of the best serves on the tour, the Aussie has been in fine form for a long time and displayed his skills once again in the final against 96th-ranked Nishioka, dishing out 12 aces in two sets. None of Kyrgios' six opponents were able to break him even once throughout the tournament.

In a press conference, the Aussie stated that with increasing age, he has become more mature and also hinted at his girlfriend as a motivating factor.

"Honestly, I feel as if I'm a lot older, a lot more mature, and I feel like when you get older, you realize you shouldn't be taking these things for granted, the way you're feeling, the way your body feels," said Kyrgios. "Also, I have a partner with me now I see a future with and I kind of see that I have to provide for. So I feel like my motivation is a lot higher than it used to be."

The majority of tennis fans have often criticized the star for his repeatedly outlandish behavior on the court, often venting frustration at the chair umpire and even his own team. Kyrgios remains unaffected and instead focuses on those who stand by him.

"I don't care about what people say about my tennis, like always disrespectful to the sport, all this, all that," admitted the 26-year old. "I know that deep down that I try really hard to do it my own way. I know that I inspire millions of people, and I'm just playing for them."

Kyrgios will face World No.31 Sebastian Baez in the first round of this week's National Bank Open (Rogers Cup).