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 father died of cancer when Mark was 16, two months before he joined the main professional tour. Selby showed potential as a teenager, but did not consistently shine until his twenties. He began his career on the UK Tour in 1998, at the time the second-level professional tour. He reached his first ranking final aged 19, the Scottish Open in 2003, where he finished runner-up to David Gray, losing 9–7 in the final. Before that, he had also already reached the semi-finals of the 2002 China Open, despite leaving his hotel room at 2 a.m. instead of 2 p.m. for