Boonen is the eighth rider to win Paris-Roubaix three times
Tom Boonen completed a hat-trick of wins at the Paris-Roubaix to join an elite group of riders who have won the cycling classic three times.
The 28-year-old Belgian, who won in 2005 and last year, became the eighth rider to achieve the feat in the 107 editions of the Queen of the Classics.
In a brutal 259km race featuring 52.9km of cobbled sections, Boonen finished 47 seconds ahead of his closest rival.
Italy's Filippo Pozzato was second with Norway's Thor Hushovd coming in third.
With 30km to go, Boonen found himself in the lead after the Carrefour de l'Arbre, an often decisive cobbled section of the race, in which three of the leading group crashed.
Spain's Juan-Antonio Flecha went down first, followed by Leif Hoste, with Hushovd then losing his balance on a turn, allowing Boonen to race clear, with Pozzato unable to challenge the Belgian.
"With all the crashes today, it was very hard, it took time for the last break to take shape," said Quick Step rider Boonen, who was banned from the 2008 Tour de France after testing positive for cocaine but won a stage of the Tour of Qatar in February.
"After Arenberg, I had a puncture and took another bike, I did not feel too well at that stage but in the finale, the others looked even worse while I kept the momentum.
"The last hour was very hard with the crashes and the fight with Pozzato. It was a battle between great riders."
But the most famous one-day cycling race was marred when an official motorcycle ran into the crowd at one point of the race, injuring 16 spectators, four of them seriously.
Other Belgian cycling greats to have won Paris-Roubaix hat-tricks include Eddy Merckx, Rik van Looy, Roger de Vlaeminck and Johan Museeuw.