Djokovic did his part improving his ideal record in US Open fourth round contests to 11-0 leaving it to Federer, who will take on Australian John Millman in the late contest on Arthur Ashe Stadium court to give the fans what would be a hotly anticipated matchup.
Still, this was a stunner.
Sept 3, 2018; New York, NY, USA; Madison Keys of the USA hits to Dominika Cibulkova of Slovakia in a fourth round match on day eight of the 2018 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center.
Djokovic appeared to struggle with a chest problem in the opening games of the third set and took a medical timeout to be accessed by the trainer.
In the fourth set, he went up a break at 4-2, yelling "Come on!" and getting all of those rowdy spectators in their "RF" gear on their feet, prompting the chair umpire to repeatedly plead for silence.
But he gave the break back in the next game after slamming an overhead into the bottom of the net on game point.
In the final tiebreaker, he double-faulted twice in a row. Both looked after their serves with only one solitary break point chance on the Federer serve before a nervy tiebreak.
The 37-year-old second-seeded Swiss will have his work cut out against the 30th-seeded Australian at Arthur Ashe Stadium. No. 30 seed Navarro defeated 22nd-seeded Sharapova 6-4, 6-3.
He now meets Novak Djokovic, something unimaginable barely five years ago, when his shoulder was so badly injured he tried a stint working the financial services company of a friend in his native Brisbane. "But at the same time, there is a little biological clock that is not really working in your favor", the No. 6-seeded Djokovic told the crowd afterward. The German reached his lone Grand Slam quarterfinal at Wimbledon in 2012.
Nishikori missed this tournament previous year and the Australian Open in January because of a wrist injury and dropped down to the second-tier Challenger Tour to begin his path back.