Williams' first match as a professional was in qualifying for the 2012 Wuxi Classic, where he lost 2–5 to Thepchaiya Un-Nooh.&lt;ref name="2012/13"&gt;&lt;/ref&gt; He won two matches, but lost in the third qualifying round three times during the season in the ranking events. Williams played in all ten of the minor-ranking Players Tour Championship events, with his best finish coming in the first European Tour Event where he beat established players Tom Ford, Robert Milkins and Jamie Cope, before losing a last frame decider to Mark Selby. It was largely down to this result which saw Williams finish 47th on the PTC Order of Merit. His season ended when he was beaten 7–10 by Li Yan in the first round of World Championship Qualifying, which saw him finish his first year on tour ranked world number 79.