Giuseppe Di Stefano, tenor

ROME - Giuseppe Di Stefano, 86, one of the greatest tenors of the 20th century and a celebrated singing partner of soprano Maria Callas, died yesterday, his wife said.

He died at home in Santa Maria Hoe, north of Milan, from head injuries sustained in a 2004 attack at his family's villa in Kenya by unidentified assailants, wife Monika Curth said. He underwent surgery twice in Mombasa before being flown to Milan; he awakened from a coma but never fully recovered.

Mr. Di Stefano, born in Sicily in 1921, made his debut in 1946 in the northern city of Reggio Emilia with Massenet's

Manon

, and went on to sing at the world's top opera houses, including Milan's La Scala, New York's Metropolitan, and in Vienna and Berlin; he appeared a number times in Philadelphia in the 1950s and '60s. He last performed in 1995.

Known for his powerful voice, Mr. Di Stefano also is remembered for his duets with Callas, who performed and recorded with him several times in the 1950s through her final tour in 1973 and '74, when they appeared at Philadelphia's Academy of Music.

Mr. Di Stefano was at the height of his career when other stars of contemporary opera were taking their first steps. Luciano Pavarotti, who died in September, had his big international break when he stood in for Mr. Di Stefano as Rodolfo in Puccini's

La Boheme

at London's Covent Garden in 1963.

At the Met, Mr. Di Stefano sang in 112 performances from 1948 to 1965, making his debut in Verdi's

Rigoletto

as the Duke.

"His musical merits have mostly to do with style, for the voice, though neither small nor ugly, is not an organ of great beauty," composer Virgil Thomson wrote in the New York Herald Tribune after that first performance. "But he has an impeccable enunciation, and he projects a phrase with style and authority. Also his personality is fresh and genuine."