1999–2000 season Grishin reached first place at the first stop of the
1999–2000 circuit in
Mount Buller, Victoria on 11 September 1999. The next day he finished in first place again. In the remaining events of the circuit that year, he finished in second place and third place once each, achieving second in aerials competition and third overall. In between the World Cup competitions, he won gold at the
2001 World Ski Championships in
Whistler-Blackcomb.
2001–2002 season He began the
2001–2002 World Cup ski season with an eighth-place finish at Mount Buller. He placed fourth and second at
Mont Tremblant,
Canada, followed by first and third place at
Lake Placid in January 2002. At the
2002 Winter Olympics in
Salt Lake City, he finished first with 251.76 points in the qualification round and advanced to the finals. He placed third overall in the finals, earning him a bronze medal. His bronze medal was the
only medal won by Belarus at that Olympics. Returning to the World Cup competition, he finished with a second, tenth, and fourth place, respectively, in the remaining three races.
2003–2004 season In the
2003–2004 World Cup, Grishin had a first-place finish at Mont Tremblant and second-place finish at Lake Placid in January 2004.
2004–2005 season In the
2004–2005 World Cup season, Grishin started four races, finishing no higher than eleventh place, On the second day at Lake Placid, he improved and finished in sixth place. In the next four races, he had two third-place finishes. He finished in eighth place after 12 races. In other races, he won a gold medal at the European Cup in Arosa, Switzerland, in December 2004 and a bronze medal in the
FIS Freestyle World Ski Championships 2005 in March at Ruka, Finland. and advanced to the finals. After jump 1 in the finals, he was placed fifth. Jump 2 elevated his standing to fourth place overall, but behind his fellow countryman
Dmitri Dashinski who finished with a silver medal. Grishin finished this skiing season with a
second place at the event in Davos, Switzerland, He finished 10th in the standings after 11 events. He finished 15th at the
2007 Freestyle World Ski Championships competition.
2008–2009 season In the
2008–2009 circuit, Grishin started with a first-place finish at Adventure Mountain in
Changchun, China, but failed to reach the podium in the remaining five races.
2009–2010 season He placed 16th place at the
2009 Freestyle World Ski Championships. Grishin reached the podium only once (in the Calgary race in January 2010) in the
World Cup races leading up to the
2010 Winter Olympics. He participated at the
Nor-Am Cup, finishing in tenth and third place. In the first jump of the finals, he scored 120.58 points and placed second. Grishin scored 127.83 points in his second jump for a total score of 248.41 points. Grishin beat the runner-up by 1.2 points
in the finals, In the
following year's World Cup, he had two third-place finishes. He also competed in the
2013 World Ski Championships. He finished 13th and did not qualify for the finals.
2014 Winter Olympics and retirement He was the flag bearer for Belarus for the
opening ceremony of the 2014 Sochi Olympics. Placing ninth in the second qualification round, he was unable to advance to the finals. He retired from the sport after this event. ==Sale of Olympic medals==