There was time when Roger Federer couldn't be beat; when he dominated Sunday's opponent Novak Djokovic four consecutive times between 2006 and 2007.
Granted, Federer was the world's top-ranked player at the time and Djokovic, 28, had never faced him before. Djokovic - now the No.1 seed - has turned the tables in 37 matches since, winning three straight finals and six of seven meeting against Federer, including this year's Wimbledon final where he defeated the Swiss legend in four sets.
Federer, 34, rolled through U.S Open play, defeating American John Isner and Frenchman Richard Gasquet without losing a set. Djokovic struggled against Feliciano Lopez in quarterfinal play before steamrolling through defending champion Marin Cilic in the semifinals.
It was all leading up to a sixth U.S. Open face-off.
"I think it's just a straight shootout," Federer said, via the New York Times. "I think that's the cool thing about our rivalry. It's very athletic."
Djokovic said that he is used to the pressure, especially since he's won just one of five previous Open finals. "I try to deal with those emotions on and off the court, and the experience of being out there and competing at the highest level for the biggest trophies has helped me reach that level again."
Federer wants to win his 18th career major and first since Wimbledon in 2012. Djokovic wants to tie their all-time series, which he trails 21-20 dating back to their first meeting nine years ago.
On Sunday, something's going to give.
When: Men's singles final - Sunday, Sept. 13, 2015
Where: Arthur Ashe Stadium, New York City, New York
Start Time: 4:00 p.m. EST
Live Stream: ESPN 3, USOpen.org
TV: ESPN