Around 1,500 young people descended on the supermarket, which was closed down nine months ago , off Bath Road where squatters had organised a huge party on Saturday (January 7) around 9pm.
Police with shields and helmets were called to the premises after security guards at the site were bombarded by hundreds of youths who barged their way through the barriers and into the building, a source from the security company which monitors the site told getwestlondon .
Around 200 police officers including police dogs as well as fire crews, the ambulance service and additional security staff arrived on site.
The main road was blocked off and a diversion was put in place while shops in the area including KFC, Sam's Chicken and Chicken Cottage were asked to close their doors early.
The anonymous source said: "Once on site, we had been told that there was a squatting rave organised with over 2,000 people inside the Morrisons ground floor.
"More police arrived on site, as well as more youths arriving on trains and buses trying to get inside from any entrance possible.
"You could hear loud music pumping out onto the streets, and hundreds of people walking around trying to get inside."
Riot police stormed into the building and officers led huge crowds of young people out of the building.
Once the premises was cleared, officers found the venue had been left in a state with balloons and canisters among other rubbish everywhere.
Tragopan Security Solutions (TSS), which currently has the key holding contract for Morrisons, was first alerted to the squatters on Thursday last week after an alarm had been set off.
Security guards responded to find squatters inside and A4 sheets on all the doors around the building claiming they had squatters rights to live there.
As a result, five security staff were placed on site 24 hours a day until a call came in on Saturday evening that a "squatters rave" had been organised and youths were turning up in packs of hundreds.
Adam Darr, TSS operations support manager who was on site, thanked the emergency services for their assistance.
"It was a very good strategic operation," he said.
"Police surrounded the building and got everyone out safely.
"A medical centre has been set up to treat anyone who had been hurt. But the fact there were no injuries was a very good thing."
It is believed the message of the rave was spread on social media and young people aged 16 to 18 from all over London descended on Hounslow.
A Metropolitan Police spokesman said: "We were called at 11pm on Saturday, January 7, to reports of an unlicensed music event on Bath Road in Hounslow.
"Officers attended. The event was ended by 2.30am and music equipment seized."
No arrests have been made.
The premises has since been locked and secured with security guards on site 24 hours a day.
Keep up to date with the latest news in west London via the free getwestlondon app.
You can even set it to receive push notifications for all the breaking news in your area.