Two goals from Rhys Griffiths helped Llanelli win the 2011 Welsh Cup at Parc y Scarlets.
Griffiths opened the scoring with a bullet header from Jason Bowen's cross after 15 minutes.
Craig Moses headed a second five minutes later before Alan Bull nodded one back for Bangor six minutes into the second half.
Griffiths smashed home his second on the hour mark and Chris Venables' drive sealed the win four minutes later.
Wales boss Gary Speed watched on as Llanelli won the Welsh Cup for the first time in their 104-year history.
By contrast it was Bangor's fourth successive appearance in the showpiece final, a run that has seen Neville Powell's side win all 22 Welsh Cup ties since he joined the north Wales club in May 2007.
Llanelli's victory means Andy Legg's team will feature in the second qualifying round of the Europa League.
Bangor will compete in the Uefa Champions League after winning the 2010/11 Welsh Premier League title.
Bangor: Smith, Hoy, Roberts, Morley, Moss, Johnston, Jones (Edwards 75), Williams (Smyth 62), Davies, Ward, Bull (Jebb 75).
Subs not used: Jukes, Oldfield.
Goals: Bull 51.
Llanelli: Morris, Kris Thomas, Jones, Venables, Wyn Thomas, Jason Bowen (Follows 74), Corbisiero, Griffiths, Holloway, Moses, Evans.
Subs not used: Legg, Richards, Orme, Giles.
Goals: Griffiths 15 & 60, Moses 20, Venables 64.
Referee: Mark Petch.