His first match as a professional was a successful one, beating Dave Harold 5–4 in the qualifying stages of the Wuxi Classic, but he lost 5–1 to amateur Oliver Brown at the venue stage. He had a run to the last 16 stage of the opening Asian PTC event of the season in the Yixing Open, but failed to qualify for the Australian Goldfields Open and Shanghai Masters.&lt;ref name="2014/15"&gt;&lt;/ref&gt; In qualifying for the International Championship Lines beat world champion and world number one Mark Selby 6–4 from 4–0 down at the mid-session interval. He continued to impress at the Haining Open by reaching his first professional semi-final after dispatching Ryan Day 4–2 with breaks of 120 and 113. He then edged out Jimmy Robertson 4–3, but was whitewashed 4–0 in the final by Stuart Bingham. He came through a wildcard match at the International, but lost 6–3 to Rod Lawler in the first round. Lines’ Asian final helped him finish fifth on their Order of Merit to make his debut in the Grand Final, where he was eliminated 4–1 by Matthew Selt in the opening round. His first season as a professional concluded with a 10–7 defeat against Mark Davis in the second round of World Championship qualifying. He finished his first season as a professional ranked world number 78.