After a 12–1 regular season record, the Ducks were selected to play in the 2015 Rose Bowl, a semi-final game in the College Football Playoff, against Florida State and Jameis Winston. Mariota was named the Offensive MVP in the 59–20 victory, after throwing for 338 yards with two passing touchdowns and rushing for 62 yards with one touchdown. With the win, Oregon faced Ohio State in the National Championship and lost by a score of 42–20. Coming into this game, he was set to clinch the All-Time lowest interception record, until the final 27 seconds where the last pass of the game was intercepted by cornerback Eli Apple. The loss to the Buckeyes was Mariota's final collegiate game as he entered the 2015 NFL Draft a few days later.
