Orica Green Edge's Simon Gerrans won the 100th Liège-Bastogne-Liège.
This classic of classic races was over 263km from Liège and finished in Ans and this race for climbers and puncheurs featured 4.730m of climbing.
Team Sky Chris Froome did not start having come back from Mallorca with a chest infection but Irishman Dan Martin, a former winner of this race started wearing the number one on his Garmin-Sharp jersey.
Six riders in Pirimin Lang (IAM Cycling), Michel Koch (Cannondale), Jacobus Venter (MTN-Whubeka), Matteo Bono (Lampre), Pieter Jakobs (Topsport Vlaanderen) and Marco Minnaard (Wanty Groupe Gobert), were able to get away and were at one stage 18.45 ahead.
With one hundred kilometres to go and after an ambulance had taken two photographers to hospital after their motobike crashed, Jan Bakelandts of Omega Pharma Quick Step and Roman Kreuziger of Tinkoff Saxo ended up on a verge.
Both riders got up and carried on chasing after the escapers who had distanced Marco Minnaard on the 7.2% Côte de Wanne and were 7.15 ahead.
World Champion Rui Costa was involved in a crash as the gap dropped to 5.31 with 76kms left and was forced to abandon.
With a lead of 2,20, the five front men went over La Redoute, amid big crowds. Matteo Bono of Lampre and Jacobus Venter of MTN got clear, leaving Lang and Jakobs chasing some 41 seconds ahead of the peloton.
After the Côte des Forges had been climbed, Bono went off on his own, as with American Alex Howe of Garmin leading the chase, some 31 seconds behind.
Bono was caught and inside the final twenty kilometres, the attacks started to happen. Local favourite Philippe Gilbert, Valverde and Nibali came to to the front as did Dan Martin.
BMC sent former Olympic champion Sammy Sanchez on the attack chasing after Arredondo and Pozzovivo who were now leading.
Sanchez was caught by the group containing Gilbert with fifteen kilometres left and the 8.6% Côte de Saint-Nicolas still to be dealt with.
Past Standard Liege's football ground and heading on roads that were used in the 2012 Tour De France towards Ans which is five kilometres out of Liege, the speed was up amongst the leading group, who caught Arredondo and Pozzovivo with eleven kilometres left.
Peter Weening was on the front for the final climb of the day - the Côte de Saint-Nicolas before Stefan Denifl of IAM Cycling got on the pedals and went away on the steep roads with Belgian flags draped from house windows as well as a fair amonunt of Italian flags in an area which has a big Italian population.
One Italian in Gaimpaolo Caruso from Sicily took this as his cue to attack. Alejandro Valderde tried to attack from the right but Gilbert was on his wheel
Giampaolo Caruso and Demonico Pozzovivo drove things on with a twelve second lead of a group which included Dan Martin.
Vincenzo Nibali of Astana tried to close the Italians who had a nine seocnd lead going into the final 1.8kms.
Under the flam rouge and Dan Martin stormed after the front two on a climb towards the finish line. Martin caught up to Caruso but fell on a bend with 300ms to go.
Orica Green Edge's Simon Gerrans came up and took the win in 6.37.43 ahead of Valverde, Kwiatkowski, Caruso, Pozzovivo, Slagter, Gilbert, Kreuziger, Moreno and Bardet.
Gerrans said to Eurosport: "It is incredible and I am not sure of my feelings right now. I have to thank my team. I did not have the legs with 30kms left but they insisted and I insisted and I did my best to stay in the highest positions and it is a dream come true to win."