Question: Who defeated American professional tennis player and former World No.1 in the sport?
Context: Andre Agassi was the defending champion but lost in the first round to David Ferrer. Albert Burke (1901 – 1958) was an Irish professional tennis player based in France.  Albert Burke was the son of Thomas Burke.  Thomas Burke was a professional tennis player when professional tennis began in the late 19th century and Albert Burke's brother Edmund Burke was also a professional tennis player .  Albert Burke won the Bristol Cup in France (the top professional tournament in the world in the 1920s), in 1924 and 1925 (beating Roman Najuch in both finals) .  He was also losing finalist in the Bristol Cup in 1926, 1929 and 1931 (losing all three finals to Karel Kozeluh) .  Burke finished second in the 1930 French Pro Championship round robin (Karel Kozeluh was first) .  At the US Pro Tennis Championships Burke was a quarter finalist in 1931 (losing to Howard Kinsey) and 1932 (losing to Bill Tilden) .  At the Wembley Championships Burke lost in the quarter finals in 1935 (losing to Ellsworth Vines) . Serena Jameka Williams (born September 26, 1981) is an American professional tennis player.  The Women's Tennis Association (WTA) has ranked her world No. 1 in singles on eight occasions, from 2002 to 2017.  She became the world No. 1 for the first time on July 8, 2002.  On the sixth occasion, she held the ranking for 186 consecutive weeks, tying the record set by Steffi Graf for the most consecutive weeks as world No. 1 by a female tennis player.  In total, she has been world No. 1 for 319 weeks, which ranks her third in the Open Era among female tennis players.  Some commentators, players and sports writers regard her as the greatest female tennis player of all time. Jonas Lars Björkman (] ; born 23 March 1972, Alvesta, Sweden) is a former World No. 4 Swedish professional tennis player.  He is also a former World No. 1 in doubles.  Björkman retired from professional tennis after competing at the 2008 Tennis Masters Cup Doubles championships. David Goffin (] ) (born 7 December 1990) is a Belgian professional tennis player who is currently ranked world No. 12 in men's singles by the Association of Tennis Professionals (ATP).  He was born in Rocourt, Liège, Belgium.  His breakthrough came when he reached the fourth round of the 2012 French Open as a lucky loser, eventually losing to Roger Federer in four sets.  Goffin has defeated several higher-ranked players such as John Isner, Stan Wawrinka, Novak Djokovic, Marin Čilić, Milos Raonic, Jo-Wilfried Tsonga, Dominic Thiem and Tomáš Berdych, the latter without losing a game.  He is the Belgian number 1 male tennis player as of 2017.  On February 20, 2017 Goffin became the first Belgian male tennis player to reach the ATP top 10. Kenneth Robert Rosewall {'1': ", '2': ", '3': 'AM, MBE', '4': "} (born 2 November 1934) is a former world top-ranking amateur and professional tennis player from Australia.  He won a record 23 tennis Majors including 8 Grand Slam singles titles and before the Open Era a record 15 Pro Slam titles and a record 35 Major finals overall.  He won the Pro Grand Slam in 1963.  Rosewall won 9 slams in doubles with a career double grand slam.  He is considered to be one of the greatest tennis players of all time.  He had a renowned backhand and enjoyed a long career at the highest levels from the early 1950s to the early 1970s.  Rosewall was one of the two best male players for about nine years and was the World No. 1 player for a number of years in the early 1960s.  He was ranked among the top 20 players, amateur or professional, every year from 1952 through 1977.  Rosewall is the only player to have simultaneously held Pro Grand Slam titles on three different surfaces (1962–1963).  At the 1971 Australian Open he became the first male player during the open era to win a Grand Slam tournament without dropping a set. Harsh Mankad born in Bombay, is a former world ranked ATP Professional tennis player from India.  He played Davis Cup for India between 2001-2010 and was the #1 singles player on the team for several of those years.  He is the grandson of world-renowned cricketer Vinoo Mankad, and the son of Indian Test cricketer and Mumbai captain Ashok Mankad and pioneer women's tennis player Nirupama Vasant.  . Anthony "Tony" Frederick Wilding (31 October 1883 – 9 May 1915) was a former world No. 1 tennis player from Christchurch, New Zealand, and a soldier killed in action during World War I. Wilding was the son of wealthy English immigrants to New Zealand and enjoyed the use of private tennis courts at their home.  He obtained a legal education at Trinity College, Cambridge and briefly joined his father's law firm.  Wilding was a first-class cricketer and a keen motorcycle enthusiast.  His tennis career started with him winning the Canterbury Championships aged 17.  He developed into a leading tennis player in the world during 1909–1914 and is considered to be a former world No. 1.  He won 11 Grand Slam tournament titles, six in singles and five in doubles, and is the first and to date only player from New Zealand to have won a Grand Slam singles title.  He also won three ILTF World Championships; the World Hard Court Championships twice and the World Covered Court Championships once. Andre Kirk Agassi ( ; born April 29, 1970) is an American retired professional tennis player and former World No. 1 who was one of the sport's most dominant players from the early 1990s to the mid-2000s.  Generally considered by critics and fellow players to be one of the greatest tennis players of all time, Agassi has been called the greatest service returner in the history of the game.  Described by the BBC upon his retirement as "perhaps the biggest worldwide star in the sport's history", Agassi compiled performances that, along with his unorthodox apparel and attitude, saw him cited as one of the most charismatic players in history.  As a result, he is credited for helping to revive the popularity of tennis during the 1990s. Marat Mubinovich Safin (Russian: Мара́т Муби́нович Са́фин ; ] , Tatar: Марат Мөбин улы Сафин "Marat Möbin uğlı Safin" ; born 27 January 1980) is a Russian politician and retired professional tennis player.  He achieved the Association of Tennis Professionals (ATP) world No. 1 singles ranking on November 20, 2000.  Nobody taller than Safin has ever reached his world number-one ranking.  Safin is the older brother of former world No. 1 WTA player, Dinara Safina.  They are the first and only brother–sister tandem in tennis history who have both achieved No. 1 rankings.  On court, Safin was famous for his emotional outbursts and sometimes fiery temper.
Answer: David Ferrer