In December 2018, Murphy was defeated by world number 124 Chen Feilong in the first round of the UK Championship. Despite taking an early lead of 3–1, Murphy lost the next five frames and lost the match 3–6. He bounced back later that month and reached the final of the Scottish Open after winning against the likes of Michael Holt, Kyren Wilson, and Judd Trump to face Mark Allen in the final. After trailing 3–6, Murphy won four frames out of the next five to level the match at 7–7, but Allen eventually claimed the title by winning 9–7. In January 2019, Murphy lost 2–6 to Barry Hawkins in the first round of the Masters. At the World Snooker Championship, Murphy whitewashed debutant Luo Honghao in the first round, winning 10–0, which is the biggest defeat in Crucible history. But he was knocked out of the tournament by Neil Robertson in the next round, losing 6–13.