Shirov is the winner of numerous international tournaments: Biel 1991, Madrid 1997 (shared first place with Veselin Topalov), Ter Apel 1997, Monte Carlo 1998, Mérida 2000, Paul Keres Memorial Rapid Tournament in Tallinn (2004, 2005, 2011,[2] 2012,[3] 2013),[4] Canadian Open Chess Championship 2005.

On the basis of this rating, he was invited to play a ten-game match against Vladimir Kramnik to select a challenger for PCA World Champion Garry Kasparov.

In May 2009, Alexei Shirov won the category 21 M-Tel Masters 2009 tournament, held in Sofia, Bulgaria.

In September 2010, Shirov participated in the Grand Slam Chess Masters preliminary tournament in Shanghai, where he faced world No.

5 Vladimir Kramnik, and Wang Hao; the top two scorers qualified for the Grand Slam final supertournament from October 9 to 15 in Bilbao against world No.

[8] Finishing with 4½/6 points, Shirov won the tournament, qualifying along with Kramnik for the Grand Slam final.

In August 2015, Shirov won the 5th Riga Technical University Open edging out Robert Hovhannisyan on tiebreak score, after both players finished on 7½/9.

[14] In March 2017, Shirov won the Mikhail Tal Memorial blitz tournament in Jūrmala scoring 9½/11 points.

[16] In September 2020, during the FIDE Online Chess Olympiad 2020, Shirov won the Gazprom Brilliancy Prize for his win as Black against Danyyil Dvirnyy in the Slav Defense, involving a queen sacrifice in a queenside attack, and achieved an overall score of 13/15 (+12−1=2) playing for the Spanish team.

Shirov is noted for his attacking style, a tendency which has led to comparisons with fellow Latvian and former world champion, Mikhail Tal, under whom he studied in his youth.