Mark Selby Open, losing 1–4. Selby won his first ranking title of the 2017/18 season by retaining the International Championship after surviving a fightback from Mark Allen, who trailed 3–8 and 7–9 in the final but the Englishman prevailed 10–7. As 2017 World Snooker Champion, Selby automatically qualified for the 2017 Champion of Champions. However, he lost in the quarter-finals to Luca Brecel by a scoreline of 4–6. At the 2017 Shanghai Masters, Selby crashed out to 2011 finalist Mark Williams in the quarter-finals 3–5. Selby's reign as the UK champion came to an end with a 3–6 defeat to Scott Donaldson
Mark Selby defeat. Despite this he finished the season as the world number one for the fourth year in a row. Selby's first semi-final of the season came at the International Championship courtesy of knocking out Neil Robertson 6–4, but he lost 9–4 to John Higgins. Selby did not drop a frame in reaching the third round of the UK Championship and saw off Jamie Jones 6–5, admitting later that his opponent had deserved to win the match. He then eliminated Dechawat Poomjaeng and Matthew Selt both 6–1, before being whitewashed 6–0 by Robertson in the semi-finals. Selby lost in the quarter-finals