Question: Who won one women's grand slam singles title at the US Open in 1990, Brian Gottfried or Gabriela Sabatini?
Context: The 2012 US Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2012 US Open.  In the final, Andy Murray defeated defending champion Novak Djokovic 7–6, 7–5, 2–6, 3–6, 6–2 to win the match.  It was the equal-longest US Open men's final in history, lasting 4 hours and 54 minutes (equalling the 1988 US Open final played by Ivan Lendl and Mats Wilander), and the equal second-longest men's final in the Open era, only behind the 2012 Australian Open final.  By winning the 2012 US Open, Murray became the first British man since Fred Perry in 1936 to win a Grand Slam singles title, and the first British man in the Open Era to do so.  The match is a significant part of the rivalry between the two players.  This match also marked a milestone for Murray, as it was his 100th match win at a grand slam tournament. Steffi Graf successfully defended her tile, defeating Monica Seles 7–5, 6–4 in the final to win the Women's Singles title at the 1996 US Open.  It was a rematch of the 1995 US Open final, where Graf defeated Seles in three sets.  It also marked the final time Seles and Graf would play each other at the US Open.  The 1996 U.S Open proved to be the last for Gabriela Sabatini, as she retired later that year.  Sabatini was twice a finalist at the U.S Open.  In the 1988 US Open final, Sabatini lost to Graf in three sets.  Two years later, at the 1990 US Open, Sabatini defeated Graf in two sets to win her only Grand Slam title. Gabriela Beatriz Sabatini (] ; born 16 May 1970) is an Argentine former professional tennis player.  She was one of the leading players on the women's circuit in the late-1980s and early-1990s.  She won one women's grand slam singles title at the US Open in 1990, the women's grand slam doubles title at Wimbledon in 1988, two WTA Tour Championships titles in 1988 and 1994, and a silver medal at the 1988 Olympic Games in Seoul. The 1988 Virginia Slims of Florida was a women's tennis tournament played on outdoor hard courts at the Boca Raton Resort & Club in Boca Raton, Florida in the United States and was part of Tier II of the 1988 WTA Tour.  The tournament ran from March 7 through March 13, 1988.  Fourth-seeded Gabriela Sabatini won the singles title and earned $60,000 first-prize money, ending a 30-match winning streak by Steffi Graf.  It was Sabatini's first win over Graf after 11 previous defeats. The Williams sisters are two professional American tennis players: Venus Williams (b. 1980), a seven-time Grand Slam title winner (singles), and Serena Williams (b. 1981), twenty-three-time Grand Slam title winner (singles), both of whom were coached from an early age by their parents Richard Williams and Oracene Price.  There is a noted professional rivalry between them – between the 2001 US Open and the 2017 Australian Open tournaments, they met in nine Grand Slam singles finals.  They became the first two players, female or male, to play in 4 consecutive grand slam singles finals from the 2002 French Open to the 2003 Australian Open; Serena famously won all 4 to complete the first of two "Serena Slams".  Between 2000 and 2016, a 17-year span, they collectively won 12 Wimbledon singles titles (Venus won 5 and Serena won 7).  By winning the 2001 Australian Open women's doubles title, they became the 5th pair to complete the Career Doubles Grand Slam and the only pair to complete the Career Doubles Golden Slam.  At the time, Venus and Serena were only 20 and 19 years old, respectively.  Since then they have gone on to add another two Olympic gold medals in the 2008 Beijing Olympics and the 2012 London Olympics.  Nearly a decade later, the duo would go on to win 4 consecutive grand slam doubles titles from 2009 Wimbledon through 2010 Roland Garros, which would catapult them to co-No.  1 doubles players on 7 June 2010.  Two weeks later, on 21 June 2010, Serena would hold the No. 1 singles ranking and Venus would be right behind her at No. 2 in singles.  Their most recent grand slam doubles titles came at the 2012 Wimbledon & 2016 Wimbledon events.  They remain very close, often watching each other's matches in support, even after one of them has been knocked out of a tournament. Steffi Graf was the two-time defending champion, but she was defeated in the final by her rival Gabriela Sabatini, in what was a rematch of the 1988 US Open final and the 1989 US Open top half semifinal.  It also proved to be the first and only time Sabatini would defeat Graf in Grand Slam competition. Leila Meskhi (Georgian: ლეილა მესხი ; born 5 January 1968) is a retired Georgian professional female tennis player.  She was ranked World No. 12 on 5 August 1991.  Her best performance at a Grand Slam came when she got to the quarter finals of the 1990 US Open, defeating Akiko Kijimuta, Natasha Zvereva, Katia Piccolini and Linda Ferrando before losing to eventual champion Gabriela Sabatini. Li Na (; ; born 26 February 1982) is a retired Chinese professional tennis player, who achieved a career-high WTA-ranking of world No. 2 on 17 February 2014.  Over the course of her career, Li won seven WTA singles titles and two Grand Slam singles titles at the 2011 French Open and 2014 Australian Open.  Li's rise to prominence came after those victories, which made her the first and only Grand Slam singles champion from East Asia and Asia as a whole.  Prior to this, she had already become the first player representing an East Asian and Asian country to appear in a Grand Slam singles final, a milestone she achieved at the 2011 Australian Open.  Li was also the runner-up at the 2013 Australian Open and 2013 WTA Tour Championships, a three-time quarterfinalist at Wimbledon and a semifinalist at the 2008 Beijing Olympic Games and 2013 US Open.  Among her other most notable accolades, she was the first Chinese player to win a WTA tour title at the Guangzhou International Women's Open in 2004, the first to reach a Grand Slam singles quarterfinal at the 2006 Wimbledon Championships, and the first to break into the world's top 10.  Her feats have sparked a major population growth of tennis players in East Asia, earning her the reputation as the region's tennis pioneer and trailblazer. Steffi Graf and Gabriela Sabatini are retired professional tennis players who played each other on 40 occasions between 1985 and 1995.  Steffi Graf was the world No. 1, whilst Sabatini reached a career high of No. 3.  They are both Grand Slam Champions, the German winning 22 titles whilst Sabatini won her only Grand Slam title against Graf.  The pair also teamed up to reach three French Open finals and won the 1988 Wimbledon crown. Brian Edward Gottfried (born January 27, 1952) is a retired tennis player from the United States who won 25 singles titles and 54 doubles titles during his professional career.  The right-hander was the runner-up at the 1977 French Open and achieved a career-high singles ranking on the ATP tour on June 19, 1977, when he became World No. 3.
Answer: Gabriela Beatriz Sabatini