[2][3] He made his Olympiad debut in Moscow 1994, leading Bulgaria to a fourth-place, defeating Garry Kasparov on board one.

In a strong run of tournament performances in 1996 he placed third at Wijk aan Zee, tied for first at Amsterdam, Vienna and Madrid,[5] won outright at Novgorod and shared first in Dos Hermanas.

[6] As early as 1996, he was being invited to events for the world's elite such as Las Palmas (5/10), the first category 21 tournament, played in December 1996, with Kasparov, Anand, Kramnik and Karpov participating.

Topalov's loss to reigning Classical World Champion Garry Kasparov at the 1999 Corus chess tournament is generally hailed as one of the greatest games ever played.

In 2002, he lost the final of the Dortmund Candidates Tournament (for the right to challenge for the rival Classical World Chess Championship) to Peter Leko.

Based on his rating, Topalov was invited to the eight-player, double round-robin FIDE World Chess Championship in San Luis, Argentina, in September–October 2005.

On 28 September 2006, Topalov's manager Silvio Danailov published a press release, casting suspicion on Kramnik's behaviour during the games.

The Bulgarian team made a public statement that Kramnik visited his private bathroom (the only place without any audio or video surveillance) unreasonably often, about fifty times per game (a number that FIDE officials later claimed to be exaggerated[11]) and made the most significant decisions in the game in the bathroom.

They also demanded that the organizers of the tournament allow journalists access to the surveillance video from Kramnik's room for games 1 through 4.

[12] The Appeals Committee that governed the match agreed, and ruled that the players' private restrooms should be closed and replaced with a shared one.

On 1 October, the Association of Chess Professionals released a statement denouncing Danailov for publicly accusing his opponent without evidence, and calling for him to be investigated by the FIDE Ethics Committee.

[16] On 14 February 2007, Topalov's manager released pictures, purporting to show cables in the ceiling of a toilet used by Kramnik during the World Championship match in Elista.

[17] On 29 July 2007, following a complaint by Kramnik's manager Carsten Hensel, the FIDE Ethics Commission sanctioned Topalov with "a severe reprimand" because of the accusations made in the interview of 14 December.

According to the Ethics Commission, "these statements were clearly defamatory and damaged the honour of Mr. Vladimir Kramnik, harming his personal and professional reputation".

[20] In May 2007, Topalov won the M-Tel Masters tournament for a third consecutive time with 5½/10, defeating then- leader Sasikiran in the final round.

[22] Topalov won the 14th Ciudad Dos Hermanas Rapid, 17–21 April 2008, defeating GM Francisco Vallejo Pons of Spain 2½–1½ in the final match by winning the first game and drawing the remaining three.

It was revealed afterwards that Topalov had found the line during his opening preparation, with the help of a powerful supercomputer loaned to him by Bulgaria's Defense Department.

[30] Anand quickly responded with a win in Game 2, employing a novelty out of the Catalan Opening that was not easily recognized by computers at the time (15.

Topalov chose to accept a pawn sacrifice by Anand, hoping to force a result and avoid a rapid chess tiebreak round.

On the way to winning M-Tel Masters in 2005, Topalov defeated former FIDE world champion Ruslan Ponomariov with the white pieces in a Queen's Indian Defense.