A 64-year-old man was hit in the face by a lit blow torch on Saturday night.
Police were called to The Crafty Scholar on Church Street in Lancaster to reports of an assault.
Officers arrived shortly after 5.30pm on August 13 to reports that someone had entered the pub and thrown a lit blow torch at someone.
The 64-year-old victim suffered some reddening to the face but declined medical treatment.
A 36-year-old man from Ulverston was arrested on suspicion of assault (ABH) and was given a conditional caution.
This incident is not thought to be connected to violence from football fans in town after the first Blackpool versus Morecambe clash.