Kazakh grandmaster Bibisara Assaubayeva needed only 23 moves to defeat 12th world chess champion Alexandra Kosteniuk, who plays for Switzerland, in the 4th round of the women's super tournament Cairns Cup-2026 in the USA. This was reported by Qazaqyia.kz citing Kursiv Media.
The 42-year-old former Russian Kosteniuk, a regular at the Cairns Cup, is clearly far from her best form. Having lost three times in a row at the start, the 12th chess queen (2008–2010) also capitulated in the game against Assaubayeva. This happened after the 23rd move of White, which the Kazakh played. In a sharp position, Alexandra allowed an inevitable loss of quality (see diagram).
Having won her first victory in St. Louis, Assaubayeva scored 2.5 points and moved up the standings. The three-time world blitz champion (2021, 2022, 2025) heads the group chasing the leader, 35-year-old Chinese player Tan Zhongyi. The 16th world champion (2017–2018) in the 4th round with White defeated current title contender Vaishali Rameshbabu from India.
In the fifth round, Bibisara will play a game with Black against Divya Deshmukh from India. At the triumphant Norway Chess-2026 tournament in Oslo, Assaubayeva defeated the 2025 World Cup winner with Black pieces. With White, the Kazakh drew with Deshmukh and lost to her in the "Armageddon".
St. Louis leader Tan Zhongyi will play Alice Lee in the 5th round. The American will have the White pieces.
The prestigious women's super tournament Cairns Cup with a prize fund of $250,000 is taking place in the Mecca of American chess, St. Louis (Missouri). The tournament is named after Jeanne Cairns Sinquefield, co-founder of the local chess club and a member of the World Chess Hall of Fame.
Ten chess players who received personal invitations from the organizers play in a round-robin format. The time control is classical – 90 minutes for 40 moves. Then 30 minutes until the end of the game, plus 30 seconds per move starting from the first.
In parallel, the men's tournament Sinquefield Cup-2026 is taking place in St. Louis, also named after Jeanne Cairns Sinquefield.
The competition with a prize fund of $475,000 includes chess crown contender Javokhir Sindarov from Uzbekistan. In the fourth round, our Assaubayeva's boyfriend, having an extra pawn, made peace on the 38th move with Anish Kumar Giri, born in St. Petersburg and playing under the Dutch flag.