Mark Selby with a shock 3–5 defeat to Andrew Pagett in the qualifying rounds of the 2013 Wuxi Classic. The tournament was the first to use a new format that required top-16 players to compete in qualifiers. In minor-ranking tournaments, Selby was runner-up in the Yixing Open, where he lost 1–4 to Joe Perry, and the Rotterdam Open, where he lost 3–4 to Mark Williams. He won the Antwerp Open, defeating Ronnie O'Sullivan 4–3 in the final. In December, in the seventh frame of his UK Championship semi-final against Ricky Walden, Selby compiled snooker's 100th officially recognised maximum break in professional competition.
Mark Selby second round of the China Open with a neck injury. His withdrawal was also a precautionary measure to be ready for the upcoming World Championship, which Selby declared himself fit for the week before the event. He played Barry Hawkins in the first round and was beaten 3–10. After the match Selby admitted he had only managed nine hours of practice in the lead up and that there were certain shots he was physically unable to play. Despite the disappointing end to the season Selby was guaranteed to end it ranked number one following Judd Trump's early exit from the