Thorson has cashed four times at the World Series of Poker, most notably finishing in 13th place at the 2006 World Series of Poker Main Event earning $907,128. The tournament was eventually won by Jamie Gold. The next year at the 2007 World Series of Poker $5,000 World Championship Limit Hold'em event, Thorson finished 3rd earning $136,493, a tournament that was eventually won by Saro Getzoyan. Three years later at the 2010 World Series of Poker Main Event, Thorson finished in 22nd place earning $317,161.