Question: Who did the professional tennis player currently ranked World No. 1 in men's singles defeat in the 2017 Barcelona Open Banco Sabadell - Singles?

full_context: Document 1: 2012 Barcelona Open Banc Sabadell: The 2012 Barcelona Open Banco Sabadell (also known as the "Torneo Godó") was a men's tennis tournament played on outdoor clay courts. It was the 60th edition of the event and it was part of the ATP World Tour 500 series of the 2012 ATP World Tour. It took place at the Real Club de Tenis Barcelona in Barcelona, Catalonia, Spain, from April 23 through April 29, 2010. Rafael Nadal won the singles title.
Document 2: 2013 Barcelona Open Banco Sabadell: The 2013 Barcelona Open Banco Sabadell (also known as the "Torneo Godó") was a men's tennis tournament played on outdoor clay courts. It was the 61st edition of the event and it was part of the ATP World Tour 500 series of the 2013 ATP World Tour. It took place at the Real Club de Tenis Barcelona in Barcelona, Catalonia, Spain, from 20 April through 28 April 2013. Rafael Nadal won his record 8th title at the tournament.
Document 3: 2010 Barcelona Open Banco Sabadell: The 2010 Barcelona Open Banco Sabadell (also known as the "Torneo Godó") was a tennis tournament played on outdoor clay courts. It was the 58th edition of the event known this year as the Barcelona Open Banco Sabadell, and was part of the ATP World Tour 500 series of the 2010 ATP World Tour. It took place at the Real Club de Tenis Barcelona in Barcelona, Catalonia, Spain, from April 19 through April 25, 2010.
Document 4: 2017 Barcelona Open Banco Sabadell – Singles: Rafael Nadal was the defending champion and successfully defended his title, defeating Dominic Thiem in the final, 6–4, 6–1.
Document 5: 2013 Rafael Nadal tennis season: The 2013 Rafael Nadal tennis season officially began on February 5 with the ATP Tournament in Viña del Mar in Chile. He lost in the final, but rebounded with victories at São Paulo and Acapulco. He then won the first Masters 1000 event of the year at Indian Wells. Nadal skipped Miami, and finished Runner up to Novak Djokovic at Monte-Carlo. He followed that with victories at Barcelona, Madrid, and then Rome. At the French Open, he defeated Djokovic in an epic semifinal that went to 9–7 in the fifth set, before thrashing David Ferrer to win his 8th Roland Garros crown. He was then stunned by Steve Darcis in the first round of Wimbledon, in what would be his only defeat prior to the semifinals all season. Limping in the final set, many people thought his season was over, however a strong summer saw Nadal win Montreal, Cincinnati, and then the U.S. Open (def. Djokovic), thus clinching the Emirates Airlines U.S. Open Series. This granted him 3.6 million US dollars in prize money, the most money earned by a tennis player at a single tournament. A few days after the U.S. Open Final, he flew to Madrid to help Spain secure their World Group Playoff spot for 2014, with a victory against Sergiy Stakhovsky. He also scored a victory in doubles with Marc Lopez. These victories gave him a 75–7 (91.46%) record in singles, and 6–1 (85.71%) record in doubles in 2013.
Document 6: Djokovic–Nadal rivalry: The Djokovic–Nadal rivalry is between tennis players Novak Djokovic and Rafael Nadal, who are engaged in a modern-day tennis rivalry. The rivalry is the most prolific of the Open Era. The two have faced each other 50 times with Djokovic leading 26–24. Between 2006–2010, this rivalry was often overshadowed by the historic Federer–Nadal rivalry, but it started to become widely recognized after they played their first Grand Slam final against each other at the 2010 US Open. The first half of the rivalry was dominated by Nadal (who led 16–7 after the 2010 season) while the second half has been dominated by Djokovic, winning 11 out the last 13 matches. It is widely considered to be one of the greatest rivalries in tennis history. It was the first rivalry to involve meetings at all 4 Grand Slam finals (including four consecutive Grand Slam finals) and a record 26 Masters Series matches. Their 2012 Australian Open final is considered to be one of the greatest matches of all time, and Mary Carillo and John McEnroe both commented that that Australian Open match and the 2013 French Open semi-final match were the two best matches played on hard and clay courts respectively. The Djokovic–Nadal rivalry was listed as the third greatest rivalry in the last decade in 2009 by "ATPworldtour.com" despite its only starting in 2006.
Document 7: 2011 Barcelona Open Banco Sabadell – Singles Qualifying: 2011 Barcelona Open Banco Sabadell – Singles Qualifying
Document 8: 2017 Barcelona Open Banco Sabadell: The 2017 Barcelona Open Banco Sabadell (also known as the "Torneo Godó") was a men's tennis tournament played on outdoor clay courts. It was the 65th edition of the event and part of the ATP World Tour 500 series of the 2017 ATP World Tour. It took place at the Real Club de Tenis Barcelona in Barcelona, Catalonia, Spain, from April 24 through April 30, 2017.
Document 9: 2014 Rafael Nadal tennis season: The 2014 Rafael Nadal tennis season officially began on 30 December 2013 with the start of the 2014 Qatar ExxonMobil Open. This season saw Nadal suffer from injuries that included a back injury, a wrist injury, and appendicitis. After losing in the final of the Australian Open where he suffered from a back injury, Nadal failed to defend his titles at Indian Wells, Barcelona, and Rome. He rebounded by claiming his 9th French Open. Prior to the North American hardcourt season, Nadal would experience another injury, this time a wrist injury which forced him to withdraw from the Rogers Cup, the Western & Southern Open and the US Open where he was the defending champion. Nadal announced on 24 October that he would not be competing for rest of the season due to appendicitis and eventually underwent surgery. Despite an injury plagued season, Nadal still ended the year at No. 3 with 4 titles.
Document 10: 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 11: 2011 Barcelona Open Banco Sabadell: The 2011 Barcelona Open Banco Sabadell (also known as the "Torneo Godó") was a tennis tournament played on outdoor clay courts. It was the 59th edition of the event known this year as the Barcelona Open Banco Sabadell, and was part of the ATP World Tour 500 series of the 2011 ATP World Tour. It took place at the Real Club de Tenis Barcelona in Barcelona, Spain, from April 16 through April 24, 2011. The defending champion was Fernando Verdasco, but was absent from the tournament in 2011.
Document 12: Juan Carlos Ferrero: Juan Carlos Ferrero Donat (] ; born 12 February 1980) is a retired professional tennis player, and a former world No. 1 player, from Spain. He captured the men's singles title at the 2003 French Open, and in September of that year, became the 21st player to hold the world No. 1 ranking. He was also the runner-up at the 2002 French Open and the 2003 US Open. His nickname is "Mosquito" due to his speed and his slight physical build. Ferrero retired from the game after the 2012 Valencia Open 500.
Document 13: Toni Nadal: Antonio Nadal Homar (born 27 February 1961 in Manacor, Mallorca) is a Spanish tennis coach. Toni Nadal is the uncle and coach of tennis player Rafael Nadal and the older brother of Spanish footballer Miguel Ángel Nadal.
Document 14: Rafael Nadal: Rafael "Rafa" Nadal Parera (] , ] ; born 3 June 1986) is a Spanish professional tennis player, currently ranked World No. 1 in men's singles. Known as "The King of Clay", he is widely regarded as the greatest clay-court player in history. His evolution into an all-court threat has established him as one of the greatest tennis players ever.
Document 15: Bartolomé Salvá Vidal: Bartolomé "Tomeu" Salvá Vidal (born November 20, 1986 in Majorca, Balearic Islands) is a Spanish tennis player. While he plays singles, he is also a doubles player, who partners with friend Rafael Nadal. In 2007 at the Open Seat Open in Barcelona, Spain, Salvá and Nadal made it to the final (on red clay, the surface that Nadal excels on), defeating Jonathan Erlich and Andy Ram (both ranked 13) and Mark Knowles and Daniel Nestor (both ranked fifth) in straight sets on both occasions. They made it to the finals, but Alexander Waske and Andrei Pavel defeated them 6–3, 7–6 (1).
ground_truth: Dominic Thiem