The showpiece showdown of the inaugural WDF World Championship produced a superb clash between the Northern Ireland thrower and his opponent from France.
The 49-year-old wrapped up the prize with a double 20 at Lakeside, collecting a winner’s cheque for £50,000 on top of the trophy.
Wins over Justin Thompson, Nick Fullwell, Jim McEwan and Richard Veenstra led to Duff moving into the final stage.
The WDF World Championship was introduced as a replacement for the defunct British Darts Organisation event.