In June, violist Joen Vasquez was awarded first place and $2,000 in the Washington International Competition sponsored by the Friday Morning Music Club Foundation. Last night, Vasquez returned to Washington for the other half of his prize, a recital at the Corcoran Gallery. His big tone and intense style made clear the reasons for his victory.

A native of Caracas, the 28-year-old Vasquez received a graduate degree from Juilliard last year. His playing at this stage reveals an impressive maturity of concept and a distinctive nobility of manner, which was evident from the first notes of the opening Haydn Divertimento.

Hindemith is like a patron saint to most violists since he played the instrument himself and wrote some splendid music for it. Vasquez chose his sonata, Op. 11, No. 4, which opens with a marvelously sensuous line that few listeners, much less violists, can resist. Vasquez responded to the work's widely ranging moods, supplying a rich, gutsy sound and plenty of emotional power.

The program also included the United States premiere of a Sonata for Viola and Piano by the Salvadoran composer, German Caceres, who was in the audience. Written in two movements, it begins with a freely flowing soliloquy for viola, which was expressively treated by Vasquez, and ends with a lyrical, even if harmonically quite independent, exchange between piano and viola. The recital ended with Brahms' E-Flat Major Sonata, Op. 12, No. 2, which Vasquez performed with authority, though not quite as expansively as the sweeping melodies demand.

Pianist Robert Kopelson offered able assistance throughout the evening.