Roubaix - Mathew Hayman stunned the favourites to become only the second Australian winner of Paris-Roubaix on Sunday.
The 37-year-old said he hadn't even dared to dream about winning the 'Hell of the North' race this year having broken his arm just five weeks ago during a race in Belgium.
But the Orica-GreenEdge rider edged out Belgian legend and four-time winner Tom Boonen in a sprint finish at the famous outdoor velodrome in Roubaix following a gruelling 257.5km ride from Compiegne, near Paris.
"Just pure disbelief, I can't believe it," said a stunned Hayman, the second Aussie to win the 'Queen of the Classics' after Stuart O'Grady in 2007.
"I broke my arm five weeks ago and missed all the racing. I raced a race in Spain last week.
"This is my favourite race, it's a race I dream of every year. This year I didn't even dare to dream."
Hayman was part of a 12-man breakaway that got clear 75km into the race but when a group of chasing favourites caught them around 65km from the end his chances seemed over.
Hayman, though, hung in there as the new lead group was whittled down bit by bit over each of the 27 cobbled sectors totalling 52.8km.
Five riders reached the velodrome together in with a chance of winning the prestigious 'Monument' race but although Norway's Edvald Boasson Hagen was the best sprinter on paper, he ran out of steam and finished fifth.
Briton Ian Stannard took third with Belgium's Sep Vanmarcke fourth.
For Boonen, 35, it was one of his last chances to win a fifth Paris-Roubaix and move clear of the record four wins he shares with Belgian compatriot Roger De Vlaeminck.
"I'm very happy with the team today and (German) Tony Martin worked really hard," said Boonen.
"I rode to win so I wanted to stay in the front group.
"I tried to attack, but Hayman made a really strong counter attack.
"I wanted to take the final bend in the lead but he overtook me just before.
Around 110km out there was a crash in the peloton on the cobbles that caught out the two pre-race favourites, world champion Peter Sagan and three-time former winner Fabian Cancellara.
Time-trial specialist Martin, Boonen's Etixx team-mate, pushed the pace at the front of the peloton as Sagan and Cancellara lost a minute.
After the breakaway was caught, Britain's Sky team looked strong 50km out, controlling the pace with four riders in the lead group.
But Gianni Moscon then crashed on a tight corner on the cobbles, bringing down team leader Luke Rowe.
Two corners later, Salvatore Puccio also hit the deck, leaving Stannard on his own.
Crashes were taking their toll elsewhere as Cancellara slipped on the cobbles, bringing down 2014 winner Niki Terpstra.
Sagan however incredibly managed to jump the stricken Swiss rider's bike and although he came off his seat and off the road, he somehow stayed upright and continued.
That crash ended Cancellara's hopes of catching up while Tour of Flanders winner Sagan, who was only 30-seconds back from the lead group, lost another 30-seconds and never again made contact with the leaders.
The cobbles whittled down the lead group to 10 but Vanmarcke attacked inside the final 20km, leaving only five riders in contention.
Vanmarcke, Boonen, Stannard and Boasson Hagen took turns to attack, with Hayman, the rank outsider amongst the group, trying to save energy.
Boonen, Hayman and Vanmarcke entered the velodrome together with Boasson Hagen leading Stannard back to the top three moments later, setting up a five man sprint.
Hayman seemed freshest and took the racing line to claim the biggest win of his career.
1. Mathew Hayman (AUS/ORI) 5hr 51min 53sec, 2. Tom Boonen (BEL/ETI) same time, 3. Ian Stannard (GBR/SKY) s.t., 4. Sep Vanmarcke (BEL/LNL) s.t., 5. Edvald Boasson Hagen (NOR/DDT) at 3sec, 6. Heinrich Haussler (AUS/IAM) 1:00, 7. Marcel Sieberg (GER/LOT) s.t., 8. Aleksejs Saramotins (LAT/IAM) s.t., 9. Imanol Erviti (ESP/MOV) 1:07, 10. Adrien Petit (FRA/DEN) 2:20, 11. Peter Sagan (SVK/TIN) s.t., 12. Maarten Wijnants (BEL/LNL) s.t., 13. Oliver Naesen (BEL/IAM) s.t., 14. Luke Rowe (GBR/SKY) s.t., 15. Ramon Sinkeldam (NED/GIA) s.t., 16. Dylan van Baarle (NED/CAN) s.t., 17. Bert De Backer (BEL/GIA) s.t., 18. Luke Durbridge (AUS/ORI) 4:40, 19. Marcus Burghardt (GER/BMC) 5:48, 20. Christophe Laporte (FRA/COF) 6:18