Question: Who beat the winner of the most men's singles titles in the Australian Open 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: 2017 Wimbledon Championships – Men's Singles: Men's Singles 2017 Wimbledon Championships Champion Roger Federer Runner - up Marin Čilić Final score 6 -- 3, 6 -- 1, 6 -- 4 Details Draw 128 (16 Q / 8 WC) Seeds 32 Events Singles men women boys girls Doubles men women mixed boys girls Legends men women seniors WC Doubles men women ← 2016 Wimbledon Championships 2018 →
Document 3: 2018 Wimbledon Championships – Men's Singles: Men's Singles 2018 Wimbledon Championships Champion Novak Djokovic Runner - up Kevin Anderson Final score 6 -- 2, 6 -- 2, 7 -- 6 Events Singles men women boys girls Doubles men women mixed boys girls Legends men women seniors WC Doubles men women ← 2017 Wimbledon Championships 2019 →
Document 4: 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 5: Tennis Masters Series records and statistics: Ivan Lendl and Novak Djokovic are the only players to win all nine events during their careers. However, since the creation of the ``Masters 1000 ''in 2009, Novak Djokovic is the only player to claim all nine ATP Masters 1000 events. Winning all nine events during a career has been called a`` Career 'Golden Masters'''. Rafael Nadal has won the most number of ATP Masters 1000 singles titles. He has won 33 titles to date. Bob Bryan and Mike Bryan have won the most doubles titles of all - time with 38.
Document 6: 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 7: 2017 Australian Open – Men's Singles: Men's Singles 2017 Australian Open Champion Roger Federer Runner - up Rafael Nadal Final score 6 -- 4, 3 -- 6, 6 -- 1, 3 -- 6, 6 -- 3 Details Draw 128 (16 Q / 8 WC) Seeds 32 Events Singles men women boys girls Doubles men women mixed boys girls Legends men women mixed WC Singles men women quad WC Doubles men women quad ← 2016 Australian Open 2018 →
Document 8: 2018 Australian Open – Men's Singles: Men's Singles 2018 Australian Open Champion Roger Federer Runner - up Marin Čilić Final score 6 -- 2, 6 -- 7, 6 -- 3, 3 -- 6, 6 -- 1 Details Draw 128 (16 Q / 8 WC) Seeds 32 Events Singles men women boys girls Doubles men women mixed boys girls Legends men women mixed WC Singles men women quad WC Doubles men women quad ← 2017 Australian Open 2019 →
Document 9: 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 10: 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 11: 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 12: 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 13: 2017 Wimbledon Championships – Men's Singles: Roger Federer achieved his record eighth Wimbledon and 19th Grand Slam men's singles title, defeating Marin Čilić in the final, 6 -- 3, 6 -- 1, 6 -- 4. Federer thus became the only male player to win the Wimbledon singles title eight times, as well as only the second man in the Open era, after Björn Borg in 1976, to win Wimbledon without losing a set. This was Federer's 70th appearance at a Grand Slam, tying the record for male players and a record - breaking 11th men's singles final at the same Grand Slam tournament. In addition, by virtue of his third - round win over Mischa Zverev, Federer won his 317th Grand Slam singles match, surpassing Serena Williams' record of 316 match wins and giving him the all - time record for the most Grand Slam singles wins by any player, male or female. The tournament marked the fifth time that Nadal and Federer won the French Open and Wimbledon respectively in the same year.
Document 14: 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.
Document 15: 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
ground_truth: Novak Djokovic
sub_queries: who has won the mens singles title in the australian open tennis tournament Answer: Roger Federer
who beat Roger Federer in the us open Answer: Novak Djokovic