A lucky loser is a sports competitor who loses a match in a knockout tournament or loses in qualifying, but who then enters the main draw, usually when another competitor withdraws during the tournament because of illness, injury, or other reasons. The lucky loser then re-enters the competition, normally in place of the withdrawn competitor.
The 2001 Canada Masters doubles was the men's doubles event of the one hundred and twelfth edition of the Canada Masters; a WTA Tier I tournament and the most prestigious men's tennis tournament held in Canada. Sébastien Lareau and Daniel Nestor were the defending champions but they competed with different partners that year, Lareau with Justin Gimelstob and Nestor with Sandon Stolle. Gimelstob and Lareau lost in the first round to Mark Knowles and Brian MacPhie, as did Nestor and Stolle to Jan-Michael Gambill and Simon Larose. Jiří Novák and David Rikl won in the final 6–4, 3–6, 6–3 against Donald Johnson and Jared Palmer.
The 2004 Cincinnati Masters was a tennis tournament played on outdoor hard courts. It was the 103rd edition of the Cincinnati Masters, and was part of the ATP Masters Series of the 2004 ATP Tour, and of the Tier III Series of the 2004 WTA Tour. Both the men's and the women's events took place at the Lindner Family Tennis Center in Mason, near Cincinnati, Ohio, United States. It was the first Cincinnati event to feature both men and women's draws since 1989.
Conchita Martínez was the defending champion but lost in the quarterfinals to Jennifer Capriati.
The 2004 China Open was a tennis tournament played on outdoor hard courts. It is the 6th edition of the China Open, and is part of the International Series of the 2004 ATP Tour, and of the Tier II of the 2004 WTA Tour. Both the men's and the women's events are held at the Beijing Tennis Center in Beijing, People's Republic of China. The men's event took place from 13 to 19 September 2004, while the women's took place the following week from 20 to 26 September 2004.
The 1999 WTA Madrid Open doubles was the doubles event of the fourth edition of the Internationaux de Strasbourg, a WTA Tier III tournament held in Madrid, Spain and part of the European clay court season. Florencia Labat and Dominique Van Roost were the defending champions, but they did not compete this year.
Jordan Kerr and Jim Thomas were the defending champions, but lost in the first round this year.
Elena Dementieva was the defending champion, but didn't participate in this competition.
The event was being held for the first time since 1997. Mahesh Bhupathi and Leander Paes were the defending champions.
The 1999 Advanta Championships of Philadelphia singles was the tennis singles event of the seventeenth edition of the Advanta Championships of Philadelphia; a WTA Tier II tournament held in Philadelphia, Pennsylvania. Steffi Graf was the defending champion but retired after Wimbledon earlier in the year.
This event was not held from 1989 onwards, so not defending champions were declared. Beth Herr and Candy Reynolds were the last champions in the 1988 edition.
Monica Seles was the defending champion, but did not compete this year.
This was the first edition of the tournament.
Jill Craybas was the defending champion, but lost in quarterfinals to Arantxa Parra Santonja.
Evgenia Kulikovskaya and Elena Tatarkova were the defending champions, but Kulikovskaya did not compete this year. Tatarkova teamed up with Martina Navratilova and lost in first round to Maria Elena Camerin and Flavia Pennetta.
Elena Bovina and Zsófia Gubacsi were the defending champions, but Bovina decided to compete in Charleston at the same week. Gubacsi teamed up with Katarina Dašković and lost in first round to wildcards Vanessa Menga and Ana Catarina Nogueira.
Tathiana Garbin and Angelique Widjaja were the defending champions, but Widjaja did not compete this year. Garbin teamed up with Caroline Schneider and lost in quarterfinals to tournament winners Petra Mandula and Patricia Wartusch.
Marie-Gaïané Mikaelian was the defending champion from 2002, but she chose not to compete in 2003.
In the first edition of the tournament, Zsófia Gubacsi won the title by defeating Maria Elena Camerin 1–6, 6–3, 7–6(7–5) in the final.
Todd Woodbridge and Mark Woodforde were the defending champions, but none competed this year.
Tripp Phillips 
Emmanuelle Gagliardi 
