WASHINGTON, April 9 (Xinhua) -- Defending champion Lleyton Hewitt of Australia was defeated 6-4, 6-3 by Argentina's Juan Ignacio Chela on Friday in the quarterfinals of the U.S. Men's Clay Court Championships.

Hewitt was outclassed by the in-form Chela, ranking 84th currently, and lost the first set 6-4. Chela continued his overwhelming performance and enjoyed a 5-0 lead in the second set. Although the Australian struggled to fight back with three straight games, Chela ended the brief rally by breaking back in the ninth game.

The fourth seeded Hewitt underwent surgery on his right hip this January and it was the first tournament for the former world No 1 after recovery.