At the 2014 Six-red World Championship Lertsattayathorn defeated defending champion Mark Davis in the last 16 before being defeated 7–2 eventual winner Stephen Maguire in the semi-final.

In 2016 Lertsattayathorn entered the Asian Snooker Championship in Doha as the 13th seed.

Lertsattayathorn went on to reach the final and defeated Mohammed Shehab 8–2 to win the championship, as a result he was given a two-year card on the professional World Snooker Tour for the 2016–17 and 2017–18.

[2] At the 2016 English Open, Lertsattayathorn beat compatriot Boonyarit Keattikun 4–3 and Michael White 4–1.

[3] Walden also beat Lertsattayathorn by a 4–3 scoreline in the second round of the Northern Ireland Open.