Nick Kyrgios reveals tragedy behind sustained success

Australian teen tennis ace Nick Kyrgios has revealed that tragedy in his life that has forced him to become a little bit 'more mature'.

After his five set victory over Federico Delboni on the opening day of the Australian Open, Kyrgios was given a marker pen to sign an autograph on the camera lens, but instead of signing his name the Australian wrote '74'.

The number '74' holds a big significance in Kyrgios' life as it was the age at which his grandmother Julianah Foster passed away on July 13 last year at an aged care home, News.com.au reported.

Kyrgios, who went down on one knee after defeating Delbonis and then looked to the heavens to honour his late grandmother, said that his grandma passed away last year, and that is something he still thinks about every day, adding that that's probably made him a little bit more mature.

Kyrgios claimed that she was practically his mother when he was a kid, adding that his mother was always working so his grandmother was taking him to tennis training every day, taking him school and picking him up from school.

Kyrgios claims that his grandmother was also living at their house so she was a massive influence.

Kyrgios stunned the world when he defeated then world number one Rafael Nadal on his way to the Wimbledon quarterfinals last year, and it is an achievement the Australian is proud his grandmother was able to witness.

Kyrgios said that his late grandmother passed just after Wimbledon, adding that he was just glad that she saw him playing, and that she finally saw him on that stage.

Kyrgios claimed that he is playing for his grandmother a little bit now, adding that every time he is out on the court, he is always thinking about something that is going to motivate him, and that's probably the reason he is starting to train harder and knuckle down a bit more now.