ATP Citi Open: Dogged Somdev stuns defending champion Dolgopolov

India's Somdev Devvarman notched up a stunning 6-3, 7-6 (7/4) victory over defending champion Alexandr Dolgopolov to advance to the pre-quarterfinals of the ATP 500 Citi Open in Washington on Tuesday.

Somdev rode on some excellent serves to see out the ninth seed Ukranian in the second round.

Somdev, who has a career-best ranking of 62, blasted nine aces against five by World No  25 Dolgopolov and connected 52 per cent of his first serves in the opening set and 51 per cent in the second set.

Somdev had just one double fault against his name -- Dolgopolov double-faulted eight times in the match.

The 28-year-old, Somdev, who had to make his way through the qualifiers, is likely to take on US eighth seed John Isner on Wednesday in the last 16.

"I'm very happy. That guy is a tough player, no question. I played really well. In the beginning he gave me a couple errors to break him," said Somdev, a two-time US college champion.

"He fought back in the second set. I was serving well. It kept me in the match. I gave myself looks on his serve. It was just confidence," he added.

"I'm pretty sharp. Physically for sure," Somdev further stated.

Photograph: Matthew Stockman/Getty Images