St Petersburg, Russia, 18 September 2013 |

Aussie Sam Groth has given eighth seed Denis Istomin an almighty scare before going down in three tight sets in the opening round of the ATP St Peterburg Open.

The Victorian battled for one hour and 46 minutes before falling 6-4 3-6 7-5, ending an impressive run at the Russian indoor event that saw him win three matches to qualify for the main draw.

Istomin will face Kazakh Andrey Golubev in the second round.

It was third ATP event since June that Groth had successfully qualified for; he has now won 13 of his past 20 matches.