Question: Who beat the oldest ATP world number one in the US Open?

full_context: Document 1: 2017 Australian Open – Men's singles final: The 2017 Australian Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2017 Australian Open. It was contested between Roger Federer and Rafael Nadal, ranked 17th and 9th in the world respectively. It was their record ninth meeting in a Grand Slam final in their rivalry, and their 1st meeting in a Grand Slam final since the 2011 French Open. In a rematch of the 2009 Australian Open final, which Nadal won in 5 sets, Roger Federer won the duel in 5 sets, beating Nadal for the first time in a Grand Slam since the 2007 Wimbledon final. He also trailed Nadal 3 -- 1 in the final set but won 5 games in a row to win the title. This ended a 6 - match losing streak against Nadal in Grand Slam events. Having lost all of their previous three encounters, this was the first time Federer defeated Nadal at the Australian Open and also marked Federer's first Grand Slam victory over Nadal outside the grass courts of Wimbledon. Federer extended his record of Grand Slam men's singles titles to 18 exceeding the previous record of 14 held by Pete Sampras.
Document 2: List of Grand Slam men's singles champions: Rank Player Total Years Australian Open French Open Wimbledon US Open Roger Federer 20 2003 -- 2018 6 8 5 Rafael Nadal 17 2005 -- 2018 11 Pete Sampras 14 1990 -- 2002 0 7 5 Novak Djokovic 13 2008 -- 2018 6 5 Roy Emerson 12 1961 -- 1967 6 6 Rod Laver 11 1960 -- 1969 Björn Borg 11 1974 -- 1981 0 6 5 0 8 Bill Tilden 10 1920 -- 1930 0 0 7 9 Fred Perry 8 1933 -- 1936 Ken Rosewall 8 1953 -- 1972 0 Jimmy Connors 8 1974 -- 1983 0 5 Ivan Lendl 8 1984 -- 1990 0 Andre Agassi 8 1992 -- 2003 14 Richard Sears 7 1881 -- 1887 0 0 0 7 William Renshaw 7 1881 -- 1889 0 0 7 0 William Larned 7 1901 -- 1911 0 0 0 7 René Lacoste 7 1925 -- 1929 0 Henri Cochet 7 1926 -- 1932 0 John Newcombe 7 1967 -- 1975 0 John McEnroe 7 1979 -- 1984 0 0 Mats Wilander 7 1982 -- 1988 0 22 Laurence Doherty 6 1902 -- 1906 0 0 5 Tony Wilding 6 1906 -- 1913 0 0 Jack Crawford 6 1931 -- 1935 0 Don Budge 6 1937 -- 1938 Stefan Edberg 6 1985 -- 1992 0 Boris Becker 6 1985 -- 1996 0 28 Frank Sedgman 5 1949 -- 1952 0 Tony Trabert 5 1953 -- 1955 0
Document 3: List of Grand Slam men's singles champions: Rank Player Total Winning Span Australian Open French Open Wimbledon US Open Roger Federer 19 15 5 8 5 Rafael Nadal 16 13 10 Pete Sampras 14 13 0 7 5 Roy Emerson 12 7 6 Novak Djokovic 12 9 6 6 Rod Laver 11 10 Björn Borg 11 8 0 6 5 0 8 Bill Tilden 10 11 0 0 7 9 Fred Perry 8 Ken Rosewall 8 20 0 Jimmy Connors 8 10 0 5 Ivan Lendl 8 7 0 Andre Agassi 8 12 14 Richard Sears 7 7 0 0 0 7 William Renshaw 7 9 0 0 7 0 William Larned 7 11 0 0 0 7 René Lacoste 7 5 0 Henri Cochet 7 7 0 John Newcombe 7 9 0 John McEnroe 7 6 0 0 Mats Wilander 7 7 0 22 Laurence Doherty 6 5 0 0 5 Tony Wilding 6 8 0 0 Jack Crawford 6 5 0 Don Budge 6 Stefan Edberg 6 8 0 Boris Becker 6 12 0 28 Frank Sedgman 5 0 Tony Trabert 5 0
Document 4: List of ATP number 1 ranked singles tennis players: Lleyton Hewitt is both the youngest world No. 1 (20 years, 268 days) and youngest year - end No. 1, while Rafael Nadal is the oldest year - end No. 1 (31 years, 211 days). Roger Federer is the oldest No. 1 (36 years, 314 days).
Document 5: List of WTA number 1 ranked tennis players: On 11 September 2017, Garbiñe Muguruza and Rafa Nadal made Spain the first country since the United States 14 years ago to simultaneously top both the ATP and the WTA rankings, with Muguruza making her debut in the No. 1 spot. The first such pair were Serena Williams and Andre Agassi, 28 April to 11 May 2003.
Document 6: Novak Djokovic: Djokovic is widely regarded as one of the greatest tennis players of all time. He has won 13 Grand Slam singles titles, five ATP Finals titles, 30 Masters 1000 series titles, 12 ATP World Tour 500 tournaments, and has held the No. 1 spot in the ATP rankings for a total of 223 weeks. In majors, he has won six Australian Open titles, four Wimbledon titles, two US Open titles and one French Open title. In 2016, he became the eighth player in history to achieve the Career Grand Slam. Following his victory at the 2016 French Open, he became the third man to hold all four major titles at once, the first since Rod Laver in 1969, and the first ever to do so on three different surfaces.
Document 7: List of ATP number 1 ranked singles tennis players: Rank Player Total 1. Federer, Roger Roger Federer 302 2. Sampras, Pete Pete Sampras 286 3. Lendl, Ivan Ivan Lendl 270 4. Connors, Jimmy Jimmy Connors 268 5. Djokovic, Novak Novak Djokovic 223 6. McEnroe, John John McEnroe 170 7. Nadal, Rafael Rafael Nadal 146 8. Borg, Björn Björn Borg 109 9. Agassi, Andre Andre Agassi 101 10. Hewitt, Lleyton Lleyton Hewitt 80 11. Edberg, Stefan Stefan Edberg 72 12. Courier, Jim Jim Courier 58 13. Kuerten, Gustavo Gustavo Kuerten 43 14. Murray, Andy Andy Murray 41 15. Năstase, Ilie Ilie Năstase 40 16. Wilander, Mats Mats Wilander 20 17. Roddick, Andy Andy Roddick 13 18. Becker, Boris Boris Becker 12 19. Safin, Marat Marat Safin 9 20. Newcombe, John John Newcombe 8 Ferrero, Juan Carlos Juan Carlos Ferrero 22. Muster, Thomas Thomas Muster 6 Ríos, Marcelo Marcelo Ríos Kafelnikov, Yevgeny Yevgeny Kafelnikov 25. Moyá, Carlos Carlos Moyá 26. Rafter, Patrick Patrick Rafter * active players - current No. 1 in bold Rank Player Consecutive 1. Federer, Roger Roger Federer 237 2. Connors, Jimmy Jimmy Connors 160 3. Lendl, Ivan Ivan Lendl 157 4. Djokovic, Novak Novak Djokovic 122 5. Sampras, Pete Pete Sampras 102 6. Jimmy Connors (2) 84 7. Pete Sampras (2) 82 8. Ivan Lendl (2) 80 9. Hewitt, Lleyton Lleyton Hewitt 75 10. McEnroe, John John McEnroe 58 11. Nadal, Rafael Rafael Nadal 56 12. John McEnroe (2) 53 Novak Djokovic (2) 14. Agassi, Andre Andre Agassi 52 15. Roger Federer (2) 48 Novak Djokovic (3) 17. Borg, Björn Björn Borg 46 Rafael Nadal (2) 19. Murray, Andy Andy Murray 41 20. Năstase, Ilie Ilie Năstase 40 * current streak in bold
Document 8: List of ATP number 1 ranked singles tennis players: Since 1973, 26 men have been ranked number 1 by the ATP, of which 17 have been year - end number 1. The current world number one is Rafael Nadal.
Document 9: 2017 Australian Open – Men's singles final: The 2017 Australian Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2017 Australian Open. It was contested between Roger Federer and Rafael Nadal, ranked 17th and 9th in the world respectively. It was their record ninth meeting in a Grand Slam final in their rivalry, and their 1st meeting in a Grand Slam final since the 2011 French Open. In a rematch of the 2009 Australian Open final, which Nadal won in 5 sets, Roger Federer won the duel in 5 sets, beating Nadal for the first time in a Grand Slam since the 2007 Wimbledon final. He also trailed Nadal 3 -- 1 in the final set but won 5 games in a row to win the title. This ended a 6 - match losing streak against Nadal in Grand Slam events. Having lost all of their previous three encounters, this was the first time Federer defeated Nadal at the Australian Open and also marked Federer's first Grand Slam victory over Nadal outside the grass courts of Wimbledon. Federer extended his record of Grand Slam men's singles titles to 18, marking the third time he broke his own all - time record, after breaking the previous record of 14, held by Pete Sampras.
Document 10: List of Grand Slam men's singles champions: Rank Player Total Years Australian Open French Open Wimbledon US Open Roger Federer 20 2003 -- 2018 6 8 5 Rafael Nadal 16 2005 -- 2017 10 Pete Sampras 14 1990 -- 2002 0 7 5 Roy Emerson 12 1961 -- 1967 6 Novak Djokovic 12 2008 -- 2016 6 6 Rod Laver 11 1960 -- 1969 Björn Borg 11 1974 -- 1981 0 6 5 0 8 Bill Tilden 10 1920 -- 1930 0 0 7 9 Fred Perry 8 1933 -- 1936 Ken Rosewall 8 1953 -- 1972 0 Jimmy Connors 8 1974 -- 1983 0 5 Ivan Lendl 8 1984 -- 1990 0 Andre Agassi 8 1992 -- 2003 14 Richard Sears 7 1881 -- 1887 0 0 0 7 William Renshaw 7 1881 -- 1889 0 0 7 0 William Larned 7 1901 -- 1911 0 0 0 7 René Lacoste 7 1925 -- 1929 0 Henri Cochet 7 1926 -- 1932 0 John Newcombe 7 1967 -- 1975 0 John McEnroe 7 1979 -- 1984 0 0 Mats Wilander 7 1982 -- 1988 0 22 Laurence Doherty 6 1902 -- 1906 0 0 5 Tony Wilding 6 1906 -- 1913 0 0 Jack Crawford 6 1931 -- 1935 0 Don Budge 6 1937 -- 1938 Stefan Edberg 6 1985 -- 1992 0 Boris Becker 6 1985 -- 1996 0 28 Frank Sedgman 5 1949 -- 1952 0 Tony Trabert 5 1953 -- 1955 0
Document 11: List of ATP number 1 ranked singles tennis players: Since 1973, 26 men have been ranked No. 1 by the ATP, of which 17 have been year - end No. 1. The current world number one is Roger Federer.
Document 12: Djokovic–Federer rivalry: The Djokovic -- Federer rivalry is a tennis rivalry between two professional tennis players, Novak Djokovic and Roger Federer. They have faced each other 45 times with Djokovic leading 23 -- 22. This includes a record 15 Grand Slam matches, four of which were finals, plus a record ten semifinals. Both players have beaten the other in each of the four Grand Slam tournaments. Federer dominated during their early slam matches, but Djokovic now has a 9 -- 6 lead in Grand Slam matches, including eight wins in the last ten meetings. A notable aspect of the rivalry is their ability to beat each other on any given day, including Grand Slam play, making it one of the most competitive and evenly matched rivalries in the Open Era. To date Federer is the only man to have beaten Djokovic in all four majors, and likewise Djokovic is the only man to have beaten Federer in all four majors. Both men accomplished this after having beaten each other at Wimbledon. Both players are generally considered to be the two greatest hard court players in the open era.
Document 13: List of ATP number 1 ranked singles tennis players: Roger Federer holds the records for both the most total weeks at No. 1 (302) and most consecutive weeks at No. 1 (237). Pete Sampras holds the record for the most year - end No. 1 (six, all consecutive). Patrick Rafter spent the fewest time at No. 1 (one week).
Document 14: List of Grand Slam men's singles champions: Rank Player Total Winning Span Australian Open French Open Wimbledon US Open Roger Federer 20 16 6 8 5 Rafael Nadal 16 13 10 Pete Sampras 14 13 0 7 5 Roy Emerson 12 7 6 Novak Djokovic 12 9 6 6 Rod Laver 11 10 Björn Borg 11 8 0 6 5 0 8 Bill Tilden 10 11 0 0 7 9 Fred Perry 8 Ken Rosewall 8 20 0 Jimmy Connors 8 10 0 5 Ivan Lendl 8 7 0 Andre Agassi 8 12 14 Richard Sears 7 7 0 0 0 7 William Renshaw 7 9 0 0 7 0 William Larned 7 11 0 0 0 7 René Lacoste 7 5 0 Henri Cochet 7 7 0 John Newcombe 7 9 0 John McEnroe 7 6 0 0 Mats Wilander 7 7 0 22 Laurence Doherty 6 5 0 0 5 Tony Wilding 6 8 0 0 Jack Crawford 6 5 0 Don Budge 6 Stefan Edberg 6 8 0 Boris Becker 6 12 0 28 Frank Sedgman 5 0 Tony Trabert 5 0
Document 15: Roger Federer career statistics: Federer has won the most grand slam tournament titles for a male player (19). He has reached the most finals (29), semifinals (42) and quarterfinals (51). He has participated in the highest number of majors (71), and the most consecutively (65). He has won the most matches at these tournaments (325). He is the only man to reach each final at least five times. He is the only man to win three tournaments five times each. He is the only man to win two of these tournaments five times consecutively. He is one of eight men to win all four majors.
ground_truth: Novak Djokovic
sub_queries: who become the oldest atp world number one Answer: Roger Federer
who beat Roger Federer in the us open Answer: Novak Djokovic