Boonen won the second stage of Paris–Nice. He won the E3 Harelbeke and Gent–Wevelgem two days later. He was favourite for the Tour of Flanders, which he won in a sprint against Filippo Pozzato and Alessandro Ballan. His third victory equalled those of Achiel Buysse, Fiorenzo Magni, Eric Leman and Johan Museeuw. His fourth win in Paris–Roubaix equalled Roger De Vlaeminck. Boonen was first to win the Tour of Flanders and Paris Roubaix double twice. He is also the first to win E3 Harelbeke, Gent–Wevelgem, Tour of Flanders and Paris–Roubaix in the same year.