In 1965, Lupu was placed fifth at the International Beethoven Piano Competition in Vienna. The following year, Lupu won the First Prize in the Second Van Cliburn International Piano Competition; he also won special prizes for the Best Performance of a Commissioned Work (of Willard Straight's "Structure for Piano") and the Best Performance of a movement from the Aaron Copland Piano Sonata. In the finals, his performance of the first movement of Sergei Prokofiev's Piano Concerto No. 2 (Op. 16), a required piece, was described by Paul Hume of The Washington Post as "the most fiery and thunderous of any of the six finalists". In addition to the Prokofiev, he performed Beethoven's Piano Concerto No. 5 (Op. 73). Alicia de Larrocha, who was on the jury, said that Lupu was a genius. "I did not expect it at all. I am just speechless," Lupu said after his victory. Shortly after the competition, in April 1967, Lupu made his debut at Carnegie Hall in New York City where he played pieces by Beethoven, Schubert, and Chopin. However, Lupu didn't do many of the other performances that came with the prize, instead choosing to return to Moscow to continue learning.