Champion Achievement in Rocket League
Win the Season Championship
How to unlock Champion
From the Main Menu select "Season". Select "Start New Season". Change the Team Size to 1v1, Difficulty to Rookie, Season Length to nine weeks and Playoff Teams to 4. Choose your Logo and Team Name and select "Continue". You need to win at least six of your games to make the Playoffs. Once you are in the Playoffs, you need to win two more matches to win the Championship.