The Londoner was seemingly out-boxed for a large portion of the fight by the Canadian-based Maduma, but came on strong in the later rounds to eventually catch-up with the visitor.
Mitchell, 29, was two rounds behind on all ringside judges’ cards before he caught Maduma early in the eleventh and proceeded to jump on the previously undefeated African.
Maduma was counted twice in the round and seemed out on his feet, although referee Phil Edwards’ decision to stop him on his feet with four seconds left in the round was harsh at best.
I had Mitchell 97-93 down at the time of the stoppage and would have given Maduma, also 29, the chance to make it to the end of the round and recover for the final session seeing how it was a world title eliminator.
Eddie Hearn will now attempt to pit Mitchell against IBF title holder Miguel Vazquez later in the year despite ‘The Hammer’ failing the pre-weight limit on Saturday morning.
Follow on Twitter @PhilDJay for tweets of upcoming news on WBN