In 1957, at the age of 16, she won the Geneva International Competition and the Ferruccio Busoni International Competition within three weeks. At the Bolzano Competition she met Arturo Benedetti Michelangeli. When she was about 20 and in the throes of an artistic crisis, she sought him out for lessons regarding her approach to music.
In 1965 she became the first pianist from the Western Hemisphere to win first prize at the Chopin Competition in Warsaw, and the following year, she made her U.S. debut in Lincoln Center's Great Performers Series. Her long association with the Deutsche Grammophon label began in 1967.
Although she plays Haydn, Mozart, Beethoven, and Schumann, her repertoire centers on composers such as Rachmaninov, Ravel, and Prokofiev, and more modern composers, including Lutoslawski and Messiaen. After the first few years of her career she gave up playing solo recitals, preferring collaborative musical work. Only her first two albums were solo.
She first publicly played chamber music when she was 17, accompanying violinist Joseph Szigeti. Especially known as a chamber-music player and as a graceful musical collaborator, she has performed with pianists Stephen Kovacevich, Nicolas Economou, Nelson Freire, and Alexandre Rabinovich, violinist Gidon Kremer, and cellist Mischa Maisky.
Among her standout recordings are those of Messiaen's Visions de l'Amen, the Piano Concerto No. 1 of Tchaikovsky, and the third concertos of Prokofiev and Rachmaninov. The Deutsche Grammophon coupling of the Tchaikovsky and Prokofiev, conducted by her then-husband, Charles Dutoit, is considered among the great classics of recorded piano concerto repertory.