Punches were thrown after six men - one of whom was arrested - attacked Mr Prescott on his arrival to Rhyl's Little Theatre at 1840BST on Wednesday.
Around 25 protesters had gathered outside the seaside town venue, an egg was seen being hurled across the road followed by jeering and whistling.
It had already been a bad day for Labour as earlier in the day Tony Blair, campaigning in Birmingham, was harangued about conditions in the health service by a relative of a cancer patient as he visited a hospital.
Sharron Storer ambushed the prime minister on the doorstep of the Queen Elizabeth Hospital, complaining that there was no bed for her partner, a cancer patient, on the bone marrow unit.
Just hours later, trouble was brewing again.
Footage shows that troubled in Rhyl flared after Mr Prescott pointed in the direction of the demonstrators.
Seconds after he walked between a group of them, the deputy prime minister could be clearly seen striking out at a protester who had thrown an egg at his back.
He can be seen grappling with the man for around 10 seconds, as party supporters struggled to separate them.
With egg splattered on his jacket and clearly shaken, Mr Prescott was then led safely into the theatre by police.
More than 30 protesters, many with placards, had gathered outside the theatre.
One poster bore the slogan "Average farming wage in Wales £75 a week" while others declared support for hunting.
The politician was reported to have been heckled the minute he stepped off the "Prescott Express" battle bus.
North Wales Police, who are setting up an incident room, later confirmed that one man had been arrested.
A short time later, a convoy of around 100 cars, lorries and tractors - led by fuel protest leader and north Wales farmer Brynle Williams - drove past the threatre where the Labour Party rally was taking place
Tooting their horns, the vehicles turned into a car park opposite the venue.
Mr Prescott, who is originally from nearby Prestatyn, has been spending the day campaigning in Wales.
Earlier, the Welsh Secretary Paul Murphy and the First Secretary in the Welsh Assembly Rhodri Morgan had been at the Welsh launch of the Labour manifesto at a college in Rhyl.
Mr Morgan went into the Little Theatre by a back entrance following the incident involving Mr Prescott.