Coria topped fellow Argentine Agustin Calleri, 6-3, 7-6 (7-4). Calleri was last year's runner-up.
Third-seeded Novak Djokovic of Serbia was an easy 6-3, 6-4, winner over Marc Gicquel of France; No. 4 seed Nicholas Massu of Chile beat former world No. 1 Carlos Moya of Spain, 7-5, 6-4; and unseeded Ruben Ramirez Hidalgo of Spain downed sixth-seeded countryman Alberto Martin, 6-2, 6-2.
Massu won this event in 2003.
Ramirez Hidalgo, who won just five matches last season, thwarted Martin's attempt to earn his 200th career victory.
Coria will make his first semifinal appearance of the year on Saturday.