Walker's first match as a professional was a 5–4 win over Cao Yupeng, who had reached the last 16 of the World Championship two months earlier. Walker lost to Peter Lines by the same scoreline in the next round.&lt;ref name="2012/13"&gt;&lt;/ref&gt; He did not win a qualifying match for a ranking event during the rest of the season. Walker fared better in the minor-ranking Players Tour Championship events as he played in all ten tournaments, with his best result coming in the Scottish Open, where he beat Andrew Pagett and Stuart Bingham, before losing 2–4 to Liang Wenbo in the last 32. He was placed 76th on the PTC Order of Merit, and finished his first year on tour ranked world number 90.