Two men and a 15-year-old boy have been stabbed at an electronic dance music gig at Blackpool's North Pier.
Police were called after a fight broke out at the Pier Jam event at about 10.45pm on Saturday.
A 23-year-old man from Manchester was taken to Royal Preston Hospital with numerous stab wounds and is in a poorly but stable condition. His injuries are not thought to be life threatening, police said.
A 30-year-old man from Bradford and a 15-year-old boy from Manchester were also taken to hospital with minor stab wounds.
Two men, aged 20 and 26, from Manchester have been arrested on suspicion of wounding and attempted murder.
Detective Inspector Gareth Willis, of Blackpool CID, said: "This was an extremely serious incident which could easily have cost at least one young man his life.
"Around 2,000 people are thought to have attended this event and I would appeal to anyone who witnessed this incident to contact us."
Anyone with information should contact police on 101 quoting log number 1121 of September 26, or Crimestoppers on 0800 555 111.