"I feel like I'm playing some great tennis right now".
epa05851034 Nick Kyrgios of Australia returns a shot to Novak Djokovic of Serbia during their match at the 2017 BNP Paribas Open tennis tournament at the Indian Wells Tennis Garden in Indian Wells, California, USA, 15 March 2017.
The 24-year-old Sock, ranked 18th, won the Delray Beach Open in February and claimed the title at the ASB Classic in Auckland the month before.
The polarising Aussie was heading into the BNP Paribas Open clash after sensationally beating second seed Novak Djokovic on Wednesday to set up the fixture against Federer.
Sock had to fend off two break points in his opening service game, but Nishikori was unable to replicate the American's feat, falling 2-0 down and failing to recover until the second set.
"Unfortunately I am unable to play today due to sickness", Kyrgios wrote on Twitter. A lot of words have been said about how great it is and I don't know that they're enough'.
And this power ballad play may be doing good things for Federer's tennis game as well.
Australian Kyrgios, meanwhile, took to twitter about an hour before the scheduled start time of his match against Federer to announce his withdrawal. "These are the matches we train for but I'm in no fit state to take to the court".
"The last time I played him here I didn't really go out on court thinking I had much of a chance", said Sock.
Sock, meanwhile, registered a pair of firsts with his quarter-final conquest of Japan's Nishikori.