Question: How many Grand Slam singles titles did the tennis player, who defeated Hana Mandlíková, during the 1988 Australian Open – Women's Singles, win?

full_context: Document 1: Hana Mandlíková: Hana Mandlíková (born 19 February 1962) is a former professional tennis player from Czechoslovakia who later obtained Australian citizenship. During her career, she won four Grand Slam singles titles: the 1980 Australian Open, 1981 French Open, 1985 US Open, and the 1987 Australian Open. She was also the runner-up at four Grand Slam singles events, including the Wimbledon finals of 1981 and 1986, and won one Grand Slam women's doubles title, the 1989 US Open with Martina Navratilova.
Document 2: Serena Williams: 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.
Document 3: Angelique Kerber career statistics: This is a list of the main career statistics of German professional tennis player, Angelique Kerber. To date, Kerber has won ten WTA singles titles including two grand slam singles titles at the 2016 Australian Open and 2016 US Open and at least one title on each playing surface (hard, clay and grass). She was also the runner-up at the 2016 Wimbledon Championships and a Silver medalist at the 2016 Rio de Janeiro Olympics. Kerber became the world No. 1 for the first time in her career on 12 September 2016.
Document 4: 1996 Wimbledon Championships – Women's Singles: Steffi Graf was the defending champion, and she successfully defended her title, defeating Arantxa Sánchez Vicario in the final, in what was a rematch of last year's final. With the victory, Graf captured her seventh and final Wimbledon crown, while it marked Sánchez Vicario's last appearance in the ladies' championship match.
Document 5: 1983 Australian Open – Women's Singles: First-seeded Martina Navratilova defeated ninth-seeded Kathy Jordan 6–2, 7–6 in the final to win the Women's Singles title at the 1983 Australian Open tennis tournament. The tournament was played on grass courts at the Kooyong Stadium in Melbourne from 29 November through 11 December 1983. Navratilova earned $75,000 prize money for winning the title, her 8th career Grand Slam singles title and her 2nd title at the Australian Open after 1981. She improved her year record to 86 wins and 1 loss. This tournament was also notable for being the first Australian Open in which Steffi Graf appeared in the main draw, and the last time that Billie Jean King appeared in the main singles draw of a grand slam.
Document 6: 1984 US Open – Women's Singles: Martina Navratilova was the defending champion, and she successfully defended her title, defeating last year's finalist Chris Evert in the final. This victory was Navratilova's sixth straight Major title, tying her with Margaret Court and Maureen Connolly for the most consecutive Grand Slam titles won. Navratilova became the first player to win Grand Slams on clay, grass and hard court on the same calendar year, after having won the French Open and Wimbledon.
Document 7: Chris Evert: Christine Marie Evert (born December 21, 1954), known as Chris Evert Lloyd from 1979 to 1987, is a former World No. 1 professional tennis player from the United States. She won 18 Grand Slam singles championships and three doubles titles. She was the year-ending World No. 1 singles player in 1974, 1975, 1976, 1977, 1978, 1980, and 1981. Overall Evert won 157 singles championships and 32 doubles titles.
Document 8: Jennifer Capriati: Jennifer Maria Capriati (born March 29, 1976) is an American former professional tennis player. A member of the International Tennis Hall of Fame, she won three singles championships in Grand Slam tournaments and a gold medal at the 1992 Summer Olympics in Barcelona, reached the World No. 1 ranking, and is considered one of the greatest tennis players of all time.
Document 9: Martina Hingis: Martina Hingis (born 30 September 1980) is a Swiss professional tennis player, a former world No. 1 singles player and currently ranked world No. 2 in doubles by the WTA. She has spent a total of 209 weeks as the singles No. 1 and has won five Grand Slam singles titles, thirteen Grand Slam women's doubles titles, winning a calendar-year doubles Grand Slam in 1998, and seven Grand Slam mixed doubles titles; for a combined total of twenty-five major titles. In addition, she has won the season-ending WTA Championships two times in singles and three times in doubles, and an Olympic silver medal.
Document 10: Althea Gibson: Althea Gibson (August 25, 1927 – September 28, 2003) was an American tennis player and professional golfer, and the first black athlete to cross the color line of international tennis. In 1956, she became the first person of color to win a Grand Slam title (the French Open). The following year she won both Wimbledon and the U.S. Nationals (precursor of the U.S. Open), then won both again in 1958, and was voted Female Athlete of the Year by the Associated Press in both years. In all, she won 11 Grand Slam tournaments, including six doubles titles, and was inducted into the International Tennis Hall of Fame and the International Women's Sports Hall of Fame. "She is one of the greatest players who ever lived," said Robert Ryland, a tennis contemporary and former coach of Venus and Serena Williams. "Martina couldn't touch her. I think she'd beat the Williams sisters." In the early 1960s she also became the first black player to compete on the women's professional golf tour.
Document 11: Evert–Mandlikova rivalry: The tennis players Chris Evert (United States) and Hana Mandlíková (Czechoslovakia/Australia) met 26 times during their careers. Evert leads their overall head-to-head series 19–7. In 1981 the rivalry was described as being the most "dramatic" in women's tennis.
Document 12: Williams sisters: 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.
Document 13: 1988 Australian Open – Women's Singles: Hana Mandlíková was the defending champion, but was defeated by Steffi Graf in the quarterfinals. Graf ended up winning the tournament, defeating Chris Evert in the final, 6–1, 7–6. This would be Chris Evert's 34 appearance in a Grand Slam final, an Open Era record, and her 6th final, Evert made the final in every Australian Open she played. This was the first Grand Slam Final played under a roof. There was an 1 hour and 23 minute delay to close the roof at 1-1 in the first set. This was Graf's first step towards completing the first and so far only calendar year Golden Slam.
Document 14: Margaret Court career statistics: This is a list of the main career statistics of Australian former tennis player Margaret Court. She won 64 Grand Slam events (24 singles, 19 doubles, 21 mixed doubles), which is a record for a male or female player. Her 24 Grand Slam singles titles and 21 in mixed doubles are also all-time records for both sexes. She achieved a career Grand Slam in singles, doubles, and mixed doubles. She is one of two women to have achieved "the" calendar year Grand Slam in singles in the Open Era (alongside Steffi Graf), and is the only woman to have achieved the mixed doubles Grand Slam, which she did twice.
Document 15: Steffi Graf: Stefanie Maria "Steffi" Graf (] ; born 14 June 1969) is a German former tennis player, who was ranked world No. 1 during her career. Graf won 22 Grand Slam singles titles. Her 22 singles titles put her second on the list of Major wins in the female competition since the introduction of the Open Era in 1968 and is third all-time behind Margaret Court (24) and Serena Williams (23). In 1988, she became the first and only tennis player (male or female) to achieve the Golden Slam by winning all four Grand Slam singles titles and the Olympic gold medal in the same calendar year. Furthermore, she is the only tennis player to have won each Grand Slam event at least four times.
ground_truth: 22