Sania Mirza (] ; born 15 November 1986) is an Indian professional tennis player who was formerly ranked No. 1 in the women's doubles rankings.
 From 2003 until her retirement from singles in 2013, she was ranked by the Women's Tennis Association as India's No. 1 player, both in singles and doubles.
 Throughout her career, Mirza has established herself as the most successful female Indian tennis player ever and one of the highest-paid and high-profile athletes in the country.
Martina Hingis and Sania Mirza were the defending champions, but chose not to participate together.
 Hingis played alongside Coco Vandeweghe, but lost in the second round to Julia Görges and Karolína Plíšková.
 Mirza teamed up with Barbora Strýcová, but lost in the second round to Gabriela Dabrowski and María José Martínez Sánchez.
Xavier Malisse (born 19 July 1980) is Belgian retired professional tennis player.
 Born in the north-western Flemish city of Kortrijk and nicknamed "X-Man", he is only one of two players from Belgium (the other being David Goffin) to have been ranked in the top 20 of the ATP tour, with a career-high singles ranking of World No. 19.
Bethanie Mattek-Sands and Sania Mirza were the defending champions, but Mattek-Sands chose not to participate.
 Mirza played alongside Cara Black, but lost to Andrea Hlaváčková and Lucie Šafářová in the first round.
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At the 2010 Asian Games in the Mixed doubles tennis event, Sania Mirza and Leander Paes were the defending champions, but only Mirza participated, as Paes was involved in the Tour Finals.
 Mirza partnered up with Vishnu Vardhan.
 They went on to win the silver medal after losing to Chan Yung-jan and Yang Tsung-hua in the final 6–4, 1–6, [2–10].
Xavier Malisse, with fellow countryman Ruben Bemelmans, defended his title, defeating Jamie Delgado and Ken Skupski 7–6, 4–6, [10–7] in the final.
 Mark Knowles and Malisse were the defending champions but Knowles decided not to participate.
Andrew Ilie was the defending champion but lost in the quarterfinals to Xavier Malisse.
 Andy Roddick won in the final 6–2, 6–4 against Malisse, which was the first title of his career.
Xavier Malisse and Dick Norman were the defending champions, but Norman chose not to participate, and only Malisse competed that year.
Xavier Malisse and Carlos Salamanca were the champions in 2008, but Malisse chose to not start this year.
Martina Hingis and Sania Mirza were the defending champions, but Mirza chose not to participate this year.
 Hingis played alongside Belinda Bencic, but lost in the first round to Gabriela Dabrowski and Michaëlla Krajicek.

Question: What sport have Sania Mirza and Xavier Malisse both played professionally?
Answer: tennis