Prakash Amritraj advanced to the quarterfinal of the USD 50,000 ATP Challenger event in Calabasas in United States after getting a walkover from his third seed opponent Jesse Levine but his doubles campaign ended with a last eight round defeat.

The wild card entrant in the singles, Prakash's first round rival - Llija Bozoljac - had also opted out of contest mid-way, due to a back problem.

In the singles quarterfinals, Prakash will now lock horns with American Michael Yani, who carved out a hard fought 7-6(6), 6-7(4), 7-6(5) win over fellow American and wild card Bradley Klahn in the second round.

In the doubles, fourth seed Prakash and Alex Kuznetsov lost 2-6, 3-6 to South African pair of Raven Klaasen and Izak van der Merwe.