Prakash Amritraj carved out a hard-fought victory over American Brian Wilson to advance to the quarter-finals of US $75,000 Comerica Challenger Series in Aptos, California.

The Indian Davis Cupper, playing on a wildcard, beat the local favourite 6-4, 2-6, 7-6(4) to set up a tough encounter against fifth seed Brunc Echagaray of Mexico in the hard-court event.

Echagaray beat American Todd Widom 6-4, 6-1.

In another ATP Challenger Series tournament in Manchester, seventh seed Rohan Bopanna is up against his doubles partner and second seed Aisam-ul-Haq Qureshi in the quarter-finals.

Qureshi beat German Lars Uebel 6-4, 6-4 to book a berth in the last-eight of the US $25,000 grass-court tournament.

Seeded third in the doubles, Bopanna and Qureshi will take on the German pair of Dominiq Meffert and Simon Stadler in the quarter-finals.