Between 1993 and 2006, Anatoly Karpov, Alexander Khalifman, Viswanathan Anand, Ruslan Ponomariov, Rustam Kasimdzhanov, and Topalov won the title of FIDE "world champion." Having not defeated Kasparov or Kramnik in match play, however, the public -- and probably the players themselves -- did not consider that they were the "legitimate" world
Kasparov – Karpov 1986 in London/LeningradResults: 12.5–11.5. Karpov had the right for a rematch. This match was restricted to 24 games. In case of a tie Kasparov would remain world champion. Kasparov won the match with one point ahead. (5 wins and 4 losses) . 727 78 191 685 294 777 914 428

garry kasparov vs anatoly karpov