![Roger Federer of Switzerland follows through on a backhand to Novak Djokovic of Serbia during their men's singles final match at the U.S. Open Championships tennis tournament in New York, September 13, Roger Federer of Switzerland follows through on a backhand to Novak Djokovic of Serbia during their men's singles final match at the U.S. Open Championships tennis tournament in New York, September 13,](https://c8.alamy.com/comp/2CK0M0Y/roger-federer-of-switzerland-follows-through-on-a-backhand-to-novak-djokovic-of-serbia-during-their-mens-singles-final-match-at-the-us-open-championships-tennis-tournament-in-new-york-september-13-2015-reutersshannon-stapleton-2CK0M0Y.jpg)
Roger Federer of Switzerland follows through on a backhand to Novak Djokovic of Serbia during their men's singles final match at the U.S. Open Championships tennis tournament in New York, September 13,
![Roger Federer of Switzerland hits a forehand to Novak Djokovic of Serbia in the Mens Semifinal at the U.S. Open Tennis Championships in Arthur Ashe Stadium in New York City on September Roger Federer of Switzerland hits a forehand to Novak Djokovic of Serbia in the Mens Semifinal at the U.S. Open Tennis Championships in Arthur Ashe Stadium in New York City on September](https://c8.alamy.com/comp/TYM18N/roger-federer-of-switzerland-hits-a-forehand-to-novak-djokovic-of-serbia-in-the-mens-semifinal-at-the-us-open-tennis-championships-in-arthur-ashe-stadium-in-new-york-city-on-september-11-2010-upijohn-angelillo-TYM18N.jpg)
Roger Federer of Switzerland hits a forehand to Novak Djokovic of Serbia in the Mens Semifinal at the U.S. Open Tennis Championships in Arthur Ashe Stadium in New York City on September
![Novak Djokovic (Serbia) in action during round 4 of US Open Championship against Stan Wawrinka (Switzerland) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo - Novak Djokovic (Serbia) in action during round 4 of US Open Championship against Stan Wawrinka (Switzerland) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -](https://c8.alamy.com/comp/2ENKX9P/novak-djokovic-serbia-in-action-during-round-4-of-us-open-championship-against-stan-wawrinka-switzerland-at-billie-jean-king-national-tennis-center-photo-by-lev-radinpacific-presssipa-usa-2ENKX9P.jpg)
Novak Djokovic (Serbia) in action during round 4 of US Open Championship against Stan Wawrinka (Switzerland) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -
![US Open 2013 Halbfinal: Stanislas Warinka gegen NovakDjokovic | Sportguide - führt Dich durch die Welt des Sports US Open 2013 Halbfinal: Stanislas Warinka gegen NovakDjokovic | Sportguide - führt Dich durch die Welt des Sports](https://www.sportguide.ch/wp-content/uploads/2013/09/Wawrinka-Djokovic-USOPEN13-RTX13BWQ-kl.jpg)
US Open 2013 Halbfinal: Stanislas Warinka gegen NovakDjokovic | Sportguide - führt Dich durch die Welt des Sports
![Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo - Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -](https://c8.alamy.com/comp/2ENKX8H/stan-wawrinka-switzerland-in-action-during-round-4-of-us-open-championship-against-novak-djokovic-serbia-at-billie-jean-king-national-tennis-center-photo-by-lev-radinpacific-presssipa-usa-2ENKX8H.jpg)
Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -
Stan Wawrinka of Switzerland is in action against Novak Djokovic of... Nachrichtenfoto - Getty Images
![Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo - Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -](https://c8.alamy.com/comp/2ENKX9F/stan-wawrinka-switzerland-in-action-during-round-4-of-us-open-championship-against-novak-djokovic-serbia-at-billie-jean-king-national-tennis-center-photo-by-lev-radinpacific-presssipa-usa-2ENKX9F.jpg)
Stan Wawrinka (Switzerland) in action during round 4 of US Open Championship against Novak Djokovic (Serbia) at Billie Jean King National Tennis Center (Photo by Lev Radin/Pacific Press/Sipa USA Stock Photo -
![Grand Slam Champions Novak Djokovic of Serbia L and Stanislas Wawrinka of Switzerland during Practice for 2018 US Open Editorial Image - Image of overhead, serbia: 222025745 Grand Slam Champions Novak Djokovic of Serbia L and Stanislas Wawrinka of Switzerland during Practice for 2018 US Open Editorial Image - Image of overhead, serbia: 222025745](https://thumbs.dreamstime.com/z/grand-slam-champions-novak-djokovic-serbia-l-stanislas-wawrinka-switzerland-practice-us-open-new-york-august-222025745.jpg)