Born in Belfast and raised in Liverpool, former cost accountant (for English Electric) Rea made his professional debut in November 1964 with a fifth round stoppage of Ken Hinds.

He won eight of his first nine fights before beating Bob Sempey in September 1965 to take the vacant BBBofC Northern Ireland Area welterweight title.

Over the next two years he had mixed results, winning five times but losing to Shaun Doyle, José Stable, Brian Curvis and Peter Cobblah.

In February 1968 he faced Vic Andreetti for the newly created British light welterweight title at the York Hall, Bethnal Green; Rea took a points decision to become British champion.

In November 1968 he travelled to the United States to face José Nápoles in a World title eliminator, losing via a fifth-round TKO.