Igor Kunitsyn claimed his first ATP Tour title on Sunday by edging out Russian compatriot Marat Safin in the final of the Kremlin Cup.
Kunitsyn, ranked 71st in the world, stunned the former world number one 7-6 (8/6) 6-7 (4/7) 6-3 in Moscow.
After taking a one-set lead, Kunitsyn looked poised to clinch the match in the second only for Safin to reel off five consecutive points in the tie-breaker to level the contest.
But the 27-year-old held his nerve to claim the decider with a solitary break in the sixth game.
Afterwards, Kunitsyn admitted: "I don't know how I was able to outplay Marat, but I guess it happens.
"I still don't understand how I won."
"Winning the title feels unreal. Playing in front of a home crowd in an all-Russian final, against one of my best buddies Marat and one of my favourite players was amazing. It was amazing to be in the final and it really is a dream come true. I wasn't expecting it."