Pettersen was selected to join the Norwegian team at the 2010 Winter Olympics in Vancouver, Canada. In his first Olympic event, the individual sprint, he placed sixth, one of three Norwegians who made it to the final competition round. He later won a gold medal with teammate Petter Northug in the team sprint event in a close finish with teams from Germany and Russia. Originally, Pettersen was not going to compete in the event, but a last-minute withdrawal by world champion Ola Vigen Hattestad due to illness left a slot open, and Pettersen was chosen to fill it. A number of teams were in contention following Pettersen's performance during the first leg of the race, and it was not until the last hill that Northug passed his opponents and took the lead entering the stadium where the race finished.