Somdev Devvarman failed to make the singles main draw of the Toronto ATP Masters after going down fighting to third seed Denis Istomin of Uzbekistan in the second round of the qualifying event.
The 14th seed Indian began well but lost 6-4, 3-6, 6-7(10) to the world number 54 Uzbek in the second and final round.
The Indian challenge at the US $2,430,000 hardcourt tournament now remains confined to the doubles event, where Laender Paes, Mahesh Bhupathi and Rohan Bopanna will compete with their respective partners.
Third seeds Paes and Czech Lukas Dlouhy have got a bye in the first round as do Bhupathi and his Belarusian partner Max Mirnyi, seeded fourth.
Bopanna who is teaming with American Eric Butorac in this event, will open his campaign against Frantisek Cermak of Czech republic and Michal Mertinak of Slovakia.