At the Riga Masters, Robertson did not lose more than one frame in any match as he reached the final. He secured his 12th ranking title with a 5–2 win over Michael Holt. Robertson reached the semi-finals of the World Open, but lost 6–2 to Joe Perry. He also played in the semi-finals of the European Masters where he was defeated 6–0 by Ronnie O'Sullivan and lost 6–3 to Peter Lines in the first round of the UK Championship. He was beaten 6–3 by O'Sullivan in the quarter-finals of the Masters and was also knocked out at the same stage of the World Grand Prix, Gibraltar Open and Players Championship. After losing 13–11 to Marco Fu in the second round of the World Championship in a performance he described as garbage, Robertson said that next season he would be playing with more passion and aggression to improve his game and make it more interesting for the viewing public.