[5][6] In 1989, he moved to the United States with his father Röstäm (also spelled Rustam), a former boxer who dominated Gata, made him study chess almost exclusively, and acted as his coach and manager.

Allen Kaufman, then Executive Director of the American Chess Foundation, helped arrange for their support after their move.

[8] In 1990, while aged 16 and still untitled, he played in the 64-player Interzonal tournament in Manila, the first step toward the World Chess Championship.

In the first round of the 1994–95 FIDE Candidates matches, Kamsky beat Paul van der Sterren (+3=3−1).

Kamsky's second round (Candidates semifinal) match against Anand, held in July and August 1994 in Sanghi Nagar, India, was more dramatic.

In the third round (Candidates final), held in Sanghi Nagar in February 1995, Kamsky routed Valery Salov 5½–1½ (+4=3−0).

In the 1994–95 PCA Candidates matches, Kamsky beat Vladimir Kramnik in the quarter-finals in New York in June, 1994.

In the March 1995 final against Anand in Las Palmas, the FIDE result was reversed, with Kamsky losing (+1=7−3).

[10][11] In 1996, Kamsky played a 20-game match against Anatoly Karpov for the FIDE World Chess Championship 1996 title at Elista in Kalmykia, losing 7½–10½ (+3=9−6).

He subsequently played in several other editions of the weekly event with mixed success, before returning to regular chess in the 2005 U.S. Championship held in November–December 2004 where he scored a respectable but unspectacular 5½–3½.

He retained this rating on the July 2005 list, but moved up to number 18, after a good unbeaten result at the 2005 HB Global Challenge tournament, held in Minneapolis in May, 2005.

A number of successes in 2007 marked his return to the playing level he had before his retirement, hinting at the possibility of becoming again a challenger for the very top of the world's chess hierarchy.

Kamsky played board one for the United States in the 2008 Chess Olympiad, held in Dresden, Germany in November.

In January 2010 Kamsky won the 52nd Reggio Emilia chess tournament (he came equal first with Zoltán Almási, defeating him in the last round, but had a better Buchholz tiebreak).

The candidates tournament began with best-of-four game match format in May 2011 in Kazan, with Kamsky facing Veselin Topalov in the quarterfinals.

[19] With a win on the Black side of the Gruenfeld defense in the second game, Kamsky held on to defeat the top-seeded Topalov 2½–1½ to advance to the semifinals.

In the round-robin stage, he drew Nakamura with black and then defeated Onischuk on the White side of the Ruy Lopez.