Robertson started season as world number four. For technical issues linked with the flight, he was not able to defend his title at the opening ranking tournament of the season, the Riga Masters. A few weeks later, Robertson reached the semi-final at the non-ranking Shanghai Masters, where he was beaten by Ronnie O'Sullivan. In November, Robertson won the invitational Champion of Champions after beating Judd Trump 10–9 in the final. However, in the first half of the season he failed to reach the quarter-final stage at any ranking tournament. As world number five, he had qualified for the Masters, but was defeated in the first round by Stephen Maguire 5–6 in spite of leading 5–1.