Kyrgios said he had vowed to be more positive and less self-critical, starting on the practice court, and - after the 6-4, 7-6 (7-3) win over Djokovic that set up a Masters 1000 quarter-final against 18-time major winner Roger Federer in Indian Wells - also emphasised the importance of the recent return from injury of his girlfriend Ajla Tomljanovic.

???"I was in a pretty dark place. Even though I was at (No.)13 last year, but I wasn't in a good place mentally at all," the 21-year-old said. "I was beating myself down, and I just wasn't in a good place. Some of that's obviously having my girlfriend back on tour - it's going to be awesome seeing her every couple of weeks. Obviously, my mum (Nill) is here. I'm just trying to stay happy and just try and enjoy my tennis a little bit, you know."

Kyrgios admitted that towards the end of a 2016 season that ended with the infamous tanking episode in Shanghai, he was "just really dreading going to tournaments, didn't want to practice, didn't want to really do anything??? I had a physical trainer for a little bit, but it was tough, because my team was motivated but I wasn't motivated.

"After Australia it was tough, as well. Obviously it felt like the whole of Australia was against me after I lost. Even though no other Australian did really well, but I copped it all, I felt. I was in a dark place, didn't want to play for a bit. I was going to take a break for who knows (how long)? I was talking to my team, like, 'I can't really play anymore'."

Instead, Kyrgios retreated to Miami to see the rehabilitating Tomljanovic, and it took a call from Davis Cup captain Lleyton Hewitt to lure him back for February's first-round Davis Cup tie against the Czech Republic at Kooyong. It was, says Kyrgios, "the best thing I could have done, come back and be with the boys, and I found some enjoyment practising again".

"Yeah, I don't know what happened. Something switched, and now I'm really enjoying it again. We still talk to this day, the whole Davis Cup team. I think that's helped me the most. You know, having some people on my side and, you know, they have my back. So that's been the key."

Admitting that his behaviour can polarise tennis fans, but claiming to be comfortable with the reality that there will be many for him and others against, Kyrgios was nevertheless passionate in his own defence.

"I don't think I'm a bad guy at all," he said. "Honestly, like, I have had a couple of mix-ups on the court, but that's in the heat of the battle, that's when you're competing or you're angry. Off the court??? I haven't done anything against the law. I haven't drink-drive (sic), haven't shot someone, I haven't stolen. In the scheme of things, you put it in perspective, I'm really not a bad person."

But, undoubtedly, a very fine tennis player seemingly destined for slam-winning greatness, his serve again impregnable against Djokovic, his power breathtaking at times. For a player who claims not to love tennis, Kyrgios is growing rather fond of beating the deposed world No.1, celebrating accordingly and admitting "that felt good to kind of prove it wasn't a one-off thing".

He now faces a faces a second career match-up against Federer, the player he rates as the best of all time, having won the first, on clay in Madrid two years ago. "I remember the first game I broke him, and I said 'come on', pretty loud, just to show that ??? he knew I would compete for every point that day. That was kind of surreal, playing him, centre court and winning was unbelievable feeling.

"I think a lot's happened since then. I have played a lot more matches. I feel more confident in my game, and he's obviously playing unbelievable at the moment. But, yeah, I remember a lot. It's completely different conditions from Madrid clay to Indian Wells in the desert. So it's going to be a completely different game."

Federer, himself an emphatic 6-2, 6-3 winner of the Australian Open finals rematch over Rafael Nadal, admitted he was "very impressed" that Kyrgios had been able to take out Djokovic, in successive tournaments, on the Serb's best surface. "I hope it's going to lead to something great for Nick, that he realises if he puts his head down and focuses that he can bring it day in and day out, week in and week out.

"That's maybe going to take a bit more time, but just that he can run through tournaments, that's why he can win tournaments, because when it matters the most against the best and in finals, he's there. Eventually he will need that, but that's a great quality to have already now." Djokovic, too, says the Canberran clearly has the game and can and should be in the top 10, or top five, if he can show the required commitment and consistency.

In the meantime, though, Kyrgios will continue to do things his way. Post-match, the still-coachless Australian retweeted an amusing social media message that suggested two early frontrunners for coach of the year: Ivan Ljubicic (coach of Federer) and Nick Kyrgios (coach of Nick Kyrgios). The latter liked it, obviously. Which, in the apparent absence of a true love for tennis, seems to be serving him pretty well now that he has emerged from the darkness and back into the light.