Maxim Iglinskiy made a late attack in Liege-Bastogne-Liege on Sunday expecting to take second place at best and ended up securing Kazakhstan's third win in seven years in cycling's oldest Classic.
The 31-year-old rider with Kazakh national team Astana caught and then shook off Italian powerhouse Vincenzo Nibali with a kilometre to go for a well-deserved solo victory by 21 seconds.
Ireland’s Daniel Martin of the Garmin-Barracuda was one of the strongest riders in the finale, coming in fifth.
Iglinskiy's team mate Enrico Gasparotto of Italy, victorious in the Amstel Gold Race Classic last week, finished third.
Iglinskiy said when he broke away from Spaniard Joaquim Rodriguez and set off in pursuit of Nibali on the agonisingly steep Cote de San Nicolas 5.5 kilometres from the finish, he thought he was racing for runner's-up spot.
"Then I saw Nibali ahead of me, and when I got close to him I could see he wasn't looking great," Iglinskiy told reporters.
"I dropped him and went away for what is the biggest win of my career. There'll be a lot of celebrating in Kazakhstan tonight. We know how important this race is."
When 2010 Tour of Spain winner Nibali broke away alone on the decisive Cote de la Roche aux Faucons climb, 18.5 kilometres from the finish, none of the major favourites could follow.
Last year's Liege-Bastogne-Liege winner Philippe Gilbert of Belgium tried but failed to organise a counter-attack, while 2006 and 2008 champion Alejandro Valverde of Spain had a mechanical problem and faded badly.
Iglinskiy said he had received a pre-race phone call from his compatriot, team mate and twice Liege-Bastogne-Liege winner Alexandre Vinokourov, advising him on a precise race strategy.
"He said that if someone like Nibali or (Spanish favourite Joaquim) Rodrguez attacked, I mustn't panic."
"Instead I had to take my time, make a move when the favourites weren't expecting it, and go for the win.
"Now I'll try and pay Alexandre back by helping him get a stage victory in the Tour de France this summer. For me, this is the biggest win of my career."