World Chess Championship Topalov, and negotiations began for a Kramnik–Topalov match to unify the title. The FIDE World Chess Championship 2006 reunification match between Topalov and Kramnik was held in late 2006. After much controversy, it was won by Kramnik. Kramnik thus became the first unified and undisputed World Chess Champion since Kasparov split from FIDE to form the PCA in 1993. Kramnik played to defend his title at the World Chess Championship 2007 in Mexico. This was an 8-player double round robin tournament, the same format as was used for the FIDE World Chess Championship 2005. This tournament was won by Viswanathan
Women's World Chess Championship 2001 2nd), Wang Lei (4th), Pia Cramling (6th), Koneru Humpy (13th), Qin Kanying (15th), Sofia Polgar (16th), and Viktorija Cmilyte (20th). Polgár, ranked 1st female and 19th overall in the world, chose instead to participate in the concurrent open event. Reigning champion Xie Jun had put her active career on hold at the time and decided not to defend her title. Women's World Chess Championship 2001 The Women's World Chess Championship 2001 took place from November 25 to December 14, 2001 in Moscow, Russia. It was won by Zhu Chen, who beat Alexandra Kosteniuk in the final by 5 to 3.