In a tight match in the quarter-finals of the World Grand Prix, King was defeated in a final leg decider against Van Gerwen as he was unable to checkout 120. He went a stage further at the European Championship, but lost 11–8 to Terry Jenkins. King continued his fine form at the Masters by beating Simon Whitlock and Justin Pipe and then produced a superb performance to exact revenge over Van Gerwen 11–9 with a 121 finish on the bull. He built on his momentum in the final against James Wade to lead 5–0 after the first session with an average of 110 and was also 9–2 in front. Wade rallied to trail 9–6 before a 158 finish from King saw him stand one leg away from his first PDC major title. However, he would miss a total of eight championship darts as Wade completed his comeback with an 11–10 win. The misses didn't seem to affect him at the Grand Slam, as he punished every mistake from Gary Anderson in a second round 10–4 win and then beat Stephen Bunting 16–9 to face Phil Taylor in the semi-finals. King couldn't keep pace with Taylor as he fell 12–2 down and, though he briefly rallied, was eliminated 16–9. Taylor also knocked King out of the Players Championship Finals, 10–7 in the second round.