Police vehicle tyres were slashed and thousands of pounds in fines were handed out during a weekend where officers had to stop partygoers who were flouting Covid-19 restrictions at illegal events.
Around 300 people gathered near Wigan on Saturday night while dozens more were turned away, a spokesman for Greater Manchester Police (GMP) said.
The unlicensed music event was reported to police at 8.45pm by the owner of a farm, on the border with Glazebury in Cheshire, who had returned to the 320-acre site to find a large number of people gathered and loud music playing.
Seven police vehicles had their tyres slashed and officers searching the site found a machete in an area of bushes, the force said.
Greater Manchester Police Assistant Chief Constable Rob Potts said: "This event was a clear and flagrant breach of the regulations in place to keep people safe and a comprehensive investigation has been launched to bring the organisers to justice."
Staff from British Transport Police, National Police Air Service and Network Rail, helped bring the event to an end.
Mr Potts added: "As well as being illegal, these events are not safe and the fact a machete was recovered from the site of this event is a worrying but important reminder that this very much remains the case."
Police said a 26-year-old man was arrested on suspicion of not providing personal details for a fixed penalty notice and a 36-year-old man was arrested for possession of class A drugs.
One woman was treated by emergency services for injuries not believed to have been caused in suspicious circumstances.