#2 Dustin Poirier
It seems hard to believe now, but back in 2011 when he debuted in the UFC after going 1-1 in the WEC, Dustin Poirier was a big underdog in his first Octagon outing. Making the move to 145lbs for the first time to take on the #1 contender at UFC Featherweight in Josh Grispi, Poirier defied the odds to defeat ‘The Fluke’ handily, and then went on a run of four wins to cement himself as a title contender.
A loss to Chan Sung Jung derailed his title hopes though, and from there Poirier settled into a role as a high-level action fighter, picking up some major wins that were offset by losses to Cub Swanson and Conor McGregor. By 2015 though, Poirier had clearly had enough of both his reputation as an action fighter and also of the cut to 145lbs.
‘The Diamond’ moved back up to 155lbs and the results were instant – he reeled off four impressive wins, and after rebounding from a surprising loss to Michael Johnson, put together another run of dominance, beating Jim Miller, Anthony Pettis, Justin Gaethje and Eddie Alvarez to cement himself as a top contender at UFC Lightweight.
2019 saw him achieve the biggest win of his career – defeating Max Holloway to claim the Interim UFC Lightweight title – and while he failed in his attempt to unify the titles in a fight with kingpin Khabib Nurmagomedov, Poirier is still clearly a top contender at 155lbs, meaning his move up in weight definitely paid off.