At the UK Open, he began his campaign with a 9–5 win over Ronnie Baxter in the third round, before recovering from 7–3 down to Ronny Huybrechts to progress 9–8. More comfortable wins over Raymond van Barneveld (9–2) and Mensur Suljović (10–3) followed before Lewis beat Mervyn King 10–6 to play Terry Jenkins in the final. Lewis thrashed him 11–1 with an average of 109.13 for his first UK Open title and a fourth major win. He had a strong start to the Premier League with 7–1 and 7–3 victories over Simon Whitlock and Phil Taylor in the opening two matches and was still in the top four after nine weeks of play. However, Lewis then lost four games in a row and went on to finish sixth in the table, to miss out on the play-offs. Lewis and Taylor could not complete a hat-trick of successive World Cup of Darts titles as they met the Netherlands in the final with Taylor losing 4–0 to Van Gerwen and Lewis being beaten 4–0 by Van Barneveld and 4–2 by Van Gerwen meaning the tie was over before Taylor's second singles match.