Enda Lynn attempts to dispossess Lee Keegan during the Division One semi-final at Croke ParkDerry's Niall Holly tries to escape the clutches of Aidan O'Shea in a keenly contested last four clashThomas Mallon and Dermot McBride challenge for the ball with Mayo's Mickey SweeneyDerry goalkeeper Thomas Mallon saves a goalbound shot from Lee KeeganKarl McKaigue leads the Derry celebrations after the final whistle at Croke ParkProlific Derry points-scorer Mark Lynch attempts to shield the ball from Brendan HarrisonMayo's Lee Keegan is shrugged off by Enda Lynn during Derry's dramatic victory over the Connacht championsJason Doherty attempts to make ground at the expense of Derry goal-scorer Kevin JohnstonMickey Sweeney sees a shot blocked by Oisin Duffy as Brian McIver's side book a place in the Division One finalJason Gibbons and Caolan O'Boyle in action during the first of Sunday's Football League Division One semi-finalsDerry's Ciaran McFaul gets to grips with Keith Higgins in a see-saw encounter at Croke ParkReferee Padraig Hughes sends off Fergal Doherty during the first half of the League semi-finalMayo players leave the field dejected after failing to beat 14-man Derry in Dublin