Winstanley went into the last round of matches at the Grand Slam of Darts knowing a win over Simon Whitlock would secure his place in the knockout stages. He produced a superb performance to win 5–1 with a 100.63 average, before seeing off Arron Monk 10–5 and Kevin Painter 16–12 to reach his first PDC major semi-final. He faced Michael van Gerwen who started the match exceptionally by leading 5–0 and 10–1 and Winstanley could never catch up as he lost 8–16.