Kyrgios opens up about 'dark thoughts' - admitting he was 'scared to lose'

Nick Kyrgios reached the third round of the Australian Open in Melbourne on Wednesday after staging a dramatic comeback against Ugo Humbert of France. Two sets to one and 5-4 down in the fourth, the volatile Aussie saved two match points before forcing a tiebreak and a decider.

He then had an altercation with chair umpire Marijana Veljovic at the start of the fifth set over the net cord technology, but broke the Humbert serve in the third game and went on to complete a 5-7, 6-4, 3-6, 7-6(2), 6-4 victory after three and-a-half hours on court.

Kyrgios will next face last year's finalist and US Open champion Dominic Thiem, after the Austrian eased past Germany's Dominik Koepfer 6-4 6-0 6-2.