Grishin began the 2002–2003 World Cup competition with a second-place finish on the first day of competition at Mount Buller, and tenth place on the second day. He finished no higher than ninth place in the four subsequent races in January 2003. He attempted to defend his World Ski Championships title at the 2003 event in Deer Valley, falling just under two points behind Dimitri Arkhipov of Russia. Returning to the World Cup competition, he finished with a second, tenth, and fourth place, respectively, in the remaining three races. He finished fifth in the aerials standings after nine races.