Canada's Hesjedal second at Amstel Gold race
Gilbert becomes 1st Belgian to win race since 1994
Philippe Gilbert of Belgium powered away on the final climb to win the Amstel Gold race on Sunday in the Netherlands.
Gilbert waited until just a few hundred metres from the line before racing clear up the steep Cauberg climb to finish two seconds ahead of Victoria's Ryder Hesjedal, with Italy's Enrico Gasparotto coming third.
Gilbert finished the 257-kilometre race in six hours, 22 minutes, 54 seconds.
"These were the most beautiful seconds of my career," Gilbert said after becoming the first Belgian cyclist to win the one-day classic since Johan Museeuw in 1994.
Alejandro Valverde, Carlos Sastre and Bradley Wiggins were among 13 riders who missed Sunday's race after their flights to the Netherlands were cancelled because of the volcanic ash cloud disrupting aviation across Europe.
The withdrawals were a further blow to the one-day classic after Lance Armstrong and Fabian Cancellara decided not to take part in the race.
Cancellara had won the previous two one-day classics, the Tour of Flanders and last week's Paris-Roubaix.
The top riders' absence was not the only ash-related headache for organizers, who also had to seek permission from Dutch authorities to use helicopters to cover the race despite a ban on flying in the country's airspace.
Gilbert looked strong throughout the race and was rarely far from the front once the peloton had reeled in a small group of riders who broke away after just five kilometres and built up a lead of up to 6 1/2 minutes.
Gilbert felt he timed his attack perfectly.
"I waited until 350 metres to go and then gave everything," he said. "This is great for me."
It was also the first victory of the year for his Omega Pharma-Lotto team.
Last year's winner, Sergei Ivanov of Russia, repeatedly attacked over the final 13 kilometres of the race but could not sustain the pace as a group of riders that included Russian teammate Alexandr Kolobnev chased him down.
Kolobnev took the lead and rode alone with about nine kilometres to go and led into the last of three climbs up the punishing Cauberg hill. But his exertions at the head of the race drained him and he was quickly swallowed up by the chasing pack on the climb to the line.