Relentless Belgian Philippe Gilbert of Team Omega Pharma-Lotto made a devastating late lone attack in the Fleche Wallone Classic to snap up a second Ardennes Classic victory in three days earlier this afternoon.

Already victorious in the 2011 Amstel Gold Race Classic in nearby southern Holland on Sunday, the Omega Pharma-Lotto rider proved unstoppable again on the 2011 La Fleche Wallone's dauntingly steep summit finish.

Gilbert ripped out of the pack with 300 metres to go to cross the line three seconds ahead of Spain's Joaquim Rodriguez while 2008 Olympic road race champion Samuel Sanchez, also of Spain, was third.

Previously convinced the Fleche Wallone suited him the least of the three Ardennes Classics, Gilbert told reporters: "It's a big surprise for me.

"Even at the start I was feeling a bit tired from Amstel Gold, but after about 60 kilometers I started to feel better.

"Then the second time [of three] we went over the Mur, none of my team-mates were present in a big break and that made me really angry -- and motivated me more."

Gilbert said although his plans to break away before the final climb had been foiled, he had used other tactics to win.

"I'd planned to make a joint move with Alexandre Vinokourov 10 kilometres to go," he said.

"That didn't work out, but then the way I charged off so far from the finish on the final climb really demoralised my rivals. They couldn't respond."

As for his prospects in taking Sunday's final Ardennes Classic, the Liege-Bastogne-Liege, Gilbert said: "It's not impossible, I don't rule out winning.

"I was already a big favourite for it, so whether I'd won, finished fifth or 10th here today didn't make much difference."

Also second in the Amstel Gold Race, Rodriguez was philosophical about his second defeat in less than a week by Gilbert.

"If anybody was going to blast away for a big win like that today, it was going to be Philippe. We already saw that at Amstel," Rodriguez, second at Fleche last year behind Australian Cadel Evans, told reporters.

Triple Tour de France winner Alberto Contador of Spain and Team Saxo Bank-SunGard slid out of contention halfway up the final climb.

"I'm recovering from a cold but I did well here last year and I really wanted to have another go," Contador, 11th, told reporters.

Gilbert's latest success continues an impressive series of Classics victories for Belgium of late, with wins for Tom Boonen in Ghent-Wevelgem, Nick Nuyens in the Tour of Flanders and Johan van Summeren in Paris-Roubaix.