His first year as a PDC player saw him finish 33rd on the ProTour Order of Merit after all 33 Players Championship, UK Open and European Tour Events had been played. This was enough to see him qualify for the World Championship as the third highest non-qualified player. The week before the tournament Winstanley practiced intensely with five-time world champion Raymond van Barneveld, playing two four- to six-hour sessions a day at the Ducthman's home with the players aiming to take out 5001 in 50 turns. Winstanley beat Mervyn King 3–2 in his debut, recovering from 1–2 down in sets and 0–2 in legs in the decider, also surviving one match dart to eventually win the final set 6–4. In his second round match, whilst trailing Vincent van der Voort 0–2 in sets and having won only one leg in the match, Winstanley hit his first televised nine-dart finish and the fifth in World Championship history. He eventually lost 2–4 having had darts at doubles to win both the fifth and sixth sets. Winstanley won the Best Newcomer at the annual PDC dinner in January 2013. His only quarter-final of 2013 came in May at the Players Championship One, where he lost 6–1 to Robert Thornton. Winstanley suffered a surprise 4–5 defeat to qualifier Dave Weston in the first round of the UK Open. Winstanley produced an encouraging 5–2 victory over Kim Huybrechts in his opening group game of the Grand Slam of Darts but followed it up with 5–1 and 5–3 defeats to Michael van Gerwen and Van der Voort to finish third and exit the tournament.