O'Sullivan began the defence of his Masters title by defeating Neil Robertson 6–4 in the first round, after having trailed 0–3. After this, he defeated Peter Ebdon 6–3 in the quarter-final. In the semi-final he beat Mark Williams 6–5, to reach his sixth Masters final in seven years. O'Sullivan met Mark Selby in the final for the second consecutive year, and lost 9–10 despite having led 9–6. In the Welsh Open, he reached the semi–finals by beating Stuart Bingham 5–1 in the first round, Jamie Cope 5–0 in the second round, and Mark Allen 5–2 in the quarter-finals, but lost 4–6 against John Higgins in the semi–finals. O'Sullivan lost 3–5 in the first round of the China Open, against 22-year-old wild card Tian Pengfei. With this, he also lost his chance to defend his official World No. 1 spot. At the World Championship, he defeated Liang Wenbo 10–7 in the first round and Mark Williams 13–10 in the second round, before losing 11–13 to Mark Selby in the quarter-finals.