India's Sumit Nagal advanced to the pre-quarterfinals of the Prague Challenger tennis tournament after his opponent Jay Clarke of Britain retired hurt here on Monday.
Nagal, ranked 127 in the world, was leading 6-3 5-7 4-1, when Clarke decided to call it quits in the second round match after playing for over two hours.
The 22-year-old Indian, playing his first competitive match since his Davis Cup encounter against Croatia's Marin Cilic in March, had received a bye in the opening round.
Nagal, seeded sixth in the tournament that also features three-time Grand Slam winner Stanislas Wawrinka, will face local favourite Jiri Lehecka in the round of 16.
Other Indians in the fray include Divij Sharan and N Sriram Balaji, who will be competing in the doubles events with separate partners.
Sharan will partner Dutchman Robin Haase and they were seeded number one. Balaji will join hands with Belgium's Kimmer Coppejans.
Nagal will also feature in the doubles with Belarusian Ilya Ivashka.
Later this month, Nagal will compete in his second Grand Slam main draw as he has received a direct entry into the US Open.