The fourth-seeded Saina took just 29 minutes to get past the unseeded Zechiri 21-12, 21-10 in a lopsided contest here.
Saina will next face another unseeded Bulgarian in Petya Nedelcheva, who rallied to defeat Ukraine’s Larisa Griga 17-21, 21-19, 21-9.
In men’s singles, Ajay Jayaram lost to fifth-seeded Peter Gade of Denmark 22-24, 12-21 in the first round.
In women’s doubles, Jwala Gutta and Ashwini Ponnappa stormed into the pre-quarterfinals after a straight-set (21-17, 21-17) victory over Dutch duo of Lotte Jonathans and Paulien van Dooremalen in a 31-minute first round contest.
Published 22 June 2011, 07:08 IST