Somdev Devvarman staged a spirited fight back to beat Korean Davis Cupper Kyu Tae Im 6-7 (7-4), 6-2, 6-2 and move to the second round of the US $50,000 ATP Challenger in Los Angeles.
After losing a hard-fought first set, the Indian ace upped the ante in the next two to cruise home.
He will take on American wild card Lester Cook in the second round.
In the doubles event, Somdev has teamed up with Treat Conrad Huey of the Philippines. They entered the event via the qualifying rounds and will take on Britain's Alex Bogdanovic and Ireland's Conor Niland in the first round.
Meanwhile, Harsh Mankad and his American partner Scott Oudsema stunned Thai second seeds Sanchai and Sonchat Ratiwatana 6-4, 6-3 to advance to the quarter-finals.