Somdev Devvarman went down fighting against Lester Cook of the US in the second round of the $50,000 ATP Challenger event in Los Angeles.
Somdev, who is India's top-ranked men's singles player, lost 6-7 (5) 5-7 against the American wild card on Wednesday.
However, in the doubles event, Somdev and Treat Conrad Huey of Philippines advanced to the quarter-finals after a 6-1, 6-2 win over Britain's Alex Bogdanovic and Ireland's Conor Niland in the first round.
They will play third seeded American pair of Todd Widom and Michael Yani in the next round.
Harsh Mankad and his American partner Scott Oudsema have already reached the last-eight stage after stunning Thai second seed Sanchai and Sonchat Ratiwatana in their opening round.
