Kyrgios threatens to walk away if he wins Slam on Sunday

NICK KYRGIOS is through to the last eight at the US Open, while simultaneously hinting that Serena Williams might not be the only retirement at this event.

There is the genuine prospect of the 27-year-old Australian winning the title on Sunday, having disposed of world No 1 and defending champion Daniil Medvedev with a superb display of controlled aggression. Yet, as at Wimbledon, Kyrgios is also suggesting that, in the event of him lifting the trophy, he might struggle to find the ambition to carry on.

‘If I win a Grand Slam, I don’t know how much motivation I’d have afterwards because it’s extremely hard to do,’ he said after his four-set victory. ‘Three more matches potentially, then we never have to play tennis again.’

The latter comment was knowingly delivered with a smile. But should all this eventuate — which it probably will not — it would be a crying shame because Kyrgios (right) is finally coming into bloom after years of erratic behaviour. He has to be the favourite to reach the final from his half of the draw, which sees him now play 27th seed Karen Khachanov, with the victor then tackling either Matteo Berrettini or Casper Ruud. The Kyrgios serve is again proving a formidable weapon. He leads the tournament ace table, by a considerable margin, on 85.

As ever the question is whether he can handle the pressure at the end of a road trip that has seen him away from home the whole summer. ‘I feel like I’m playing for a lot more than myself,’ he said. ‘I’ve got a lot of support and on the flipside I got a lot of people doubting me and trying to bring me down as well. I’ve been in some really tough situations mentally and really scary places. ‘We don’t get to see our family like other tennis players do the majority of time. I’m trying to make it worthwhile, trying to make it a memorable ride for all of us. Hopefully we can get it done, go back home and really celebrate. ‘I’m finally able to show it now, I feel like I’ve really been working. I’ve got a lot of motivation at the moment.’ Medvedev’s take was notable and ominous for future opponents of Kyrgios: ‘I’ve played Novak, Rafa, they play amazing. Nick tonight played their level, in my opinion. He has a bit of a different game because he’s not a grinder.’