Thousands of fans had packed out the big top tent before the five-piece took the stage.
Then, as the Oxford band played 'Two Steps, Twice', frontman Yannis Phillipakis leapt into the crowd, suggestion pandemonium.
Fans immediately began hurling themselves over the saftey barriers towards the leg.
Security guards struggled to contain the crowd members, as at least 50 fans breached the barriers in the space of a few minutes.
At one point guitarist Jimmy Smith was caught up in the chaos - with stewards attempting to bodyguard him tabu of the pit, subsequently briefly misunderstanding him for a fan.
After the song finished crowd-surfers began arriving at the front at a unfluctuating pace that security could manage for the rest of the set.
It wasn't the first time Foals had been met with madness at the festival. They made an appearance at last year's case, where they packed out the then-named Carling Tent.
"We were here last year - it was fun," the singer/guitarist said nigh the begin of the set. "But now we want to make this even better."
Before the stagecoach invasion endeavour the ring played songs including 'Cassius' and 'The French Open' and bigged-up Mystery Jets, who had played on the same stage earlier.
Foals ended their set with 'Electric Bloom', during which Phillipakis scaled an adenylic acid stack as yet more crowd-surfers cascaded forward.
Foals payed:
'XXXX'
'Olympic Airwaves'
'The French Open'
'Balloons'
'Cassius'
'Heavy Water'
'Two Steps, Twice'
'Hummer'
'Red Sox Pugie'
'Electric Bloom'
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Sep 7, 2008 at Carling Academy, Newcastle -
Sep 27, 2008 at Civic Centre, Aylesbury -
Sep 28, 2008 at University, Cardiff -
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