Winstanley earned a place in the European Darts Trophy, where he overcame Gino Vos, Jamie Caven, Ian White and Peter Wright en route to reach his first appearance in the semi-finals of a European tour event, but lost there again against Michael van Gerwen. He defeated Michael Smith 2–1 in sets at the World Grand Prix, before being eliminated 3–1 by Van Gerwen in the second round. A first round exit at the European Championship followed and Winstanley was knocked out of the Grand Slam in the group stage after failing to win any of his three games. However, he found his form at the Players Championship Finals by averaging 103.94 in a 6–3 triumph over Simon Whitlock and then beat Jelle Klaasen 10–5 to play in his first major PDC quarter-final. He took an early 3–0 lead over Vincent van der Voort, but went on to lose 10–8.