New Delhi, Aug 20 - On a day when all matches were straight-set affairs, top seed Vishnu Vardhan was the lone Indian to make the semi-finals of the $10,000 International Tennis Federation (ITF) tournament at the DLTA complex here Thursday.

Vishnu defeated compatriot Rupesh Roy, 6-3, 6-2, beating him for the second successive time in less than two months.

Vishnu now plays fifth-seeded Dutch Peter Lucassen who advanced to the last four stage after the promising N. Vijay Sundar Prashanth retired trailing 6-7(3), 0-2 due to a knee problem. The Indian has had a good run in the tournament, taking out fourth-seed Rohan Gajjar and former hadrcourt national champion Ashutosh Singh in the first two rounds.

Lucassen had also got a walkover in his previous match, another Indian Jeevan Nedunchezhiyan retiring mid-way with cramps.

In another quarter-final match, sixth-seeded Ranjeeth Virali-Murugesan of India was outclassed by second-seeded South Korean Young-Jun Kim 6-0, 6-2.