Chennai : Top seed Marin Cilic was stunned 6-7 (5), 7-5, 5-7 by Jozef Kovali in the second round of the Chennai Open tennis tournament here on Wednesday. World No.6 Cilic was heavily tipped to win the hard court tournament but he was below his best against the 117-ranked Slovakian, going down in 2 hours 49 minutes at the Stadium Court. -Agency