Career
A former kart racer, Ketomaa started rallying in 1995. He made his World Rally Championship debut in 2000 at Rally Finland. In 2008, he competed a full season in the Production World Rally Championship, finishing the season third in the standings.
Ketomaa regained the Finnish Group North title in 2009.
He also made his debut in a World Rally Carolina at 2009 Rally Finland, finishing seventh overall. In 2010, Ketomaa is competing in the Super 2000 World Rally Championship in a Ford Fiesta S2000.
In 2011 Ketomaa raced in Rally Finland with Ford Fiesta RS WRC and lead after first special stage but later retired from top 5 position.