Haas, the second seed, struggled but posted a 5-7, 7-6 (7-2), 6-2 victory over Andrei Pavel of Romania in the second round Thursday. Haas reached the final here in 2000, losing to Franco Squillari.
El Aynaoui, the sixth seed, reached the quarterfinals for the sixth time this year with a 6-4, 4-6, 6-4 triumph over Bohdan Ulihrach of the Czech Republic. El Aynaoui has two titles in 2002,including one on clay in Casablanca.
France's Julien Boutter is in the quarterfinals for the third time this year as he upset fourth seed Jiri Novak of the Czech Republic, 6-2, 7-5.
Russia's Mikhail Youzhny also advanced in the second round Thursday, posting a 7-6, (7-4), 7-6 (7-2) victory over Oliver Gross of Germany.