[5][6] For the rest of the season, Lines continued to enter PTC and amateur events, with his most notable result being a 4–2 over professional Scott Donaldson in the 2013 Ruhr Open.

He qualified for the International Championship by beating Gary Wilson 6–3 and then won a match at a ranking event for the first time in his career by eliminating Noppon Saengkham 6–4, before losing by a reversal of this scoreline to David Gilbert.

[20] He made it through to the second round of the UK Championship with a 6–2 victory over Cao Yupeng, but was then whitewashed 6–0 by world number one Mark Selby.

[21] A second last 16 showing in the European Tour events came at the Gibraltar Open and was ended by Alfie Burden, but Lines finished 35th on the Order of Merit.

[23] At the 2016 Indian Open, Lines reached the last 16 of a ranking event for the first time by beating Graeme Dott 4–1 and Andrew Higginson 4–2, but lost 4–2 to Shaun Murphy.

After defeating Martin O'Donnell at the UK Championship, Lines knocked out world number three Judd Trump 6–2 and said it was the first time he had played well in a televised match.