INDIAN WELLS, Calif -- 17th seed Jack Sock stunned 4th seed Kei Nishikori in the quarterfinal match of the BNP Paribas Open, scoring his first Top 5 win.
The American jumped to an early lead with a break in the second game to go up 2-0. This was the only break he needed as it was enough to close out the set 6-3.
The Japanese superstar came back strong in the second set, jumping to a 4-1 lead and eventually taking the set 6-2.
Sock regrouped in the third, dominating the 4th seed, losing only two games in the set. He wrapped up the match 6-3, 2-6, 6-2.
This was Sock's fourth three-sets match in four matches.
"Yeah, I feel good physically," said Sock after his match. "I actually feel almost stronger as the tournament has gone on. You know, I have done the proper recovery and everything I need to after matches."
The 24-year-old is having a great start of the season, having won Auckland Open and Delray Beach. He contributes his success to the work he put in off-season.
"I think it's the offseason," he informed. "Just put in -- made some changes, put in a lot of good work, physically, mentally, everything put together. I think it's showing this year.
"But obviously physically I think I have been making the right strides for some time now. I just kept adding to it in the offseason. But I think the mental side of it is probably the biggest difference so far this year," said Sock.
The American faces Roger Federer, who had a walk-over after Nick Kyrgios withdrew earlier today citing food poisoning.