McLean's first unlicensed boxing match came about as a result of a chance meeting while in his late teens: when his car broke down in the Blackwall Tunnel he abandoned it and went to buy a replacement from an associate known as Kenny Mac, a gypsy used-car salesman in Kingsland Road, Hackney, only to find the replacement quickly failed too. McLean returned later to demand his money back, but instead of refunding McLean, Mac offered to give McLean a new car in exchange for him fighting in one of Mac's unlicensed boxing bouts later that night in Mac's yard. McLean's opponent lasted less than a minute against him, earning McLean £500, a considerable prize at the time. Mac and McLean became friends and on numerous later bouts Mac acted as McLean's boxing manager, with McLean subsequently becoming the best-known bare-knuckle street fighter in Britain.