Donegal 4-9 Monaghan 1-5
Tyrone 2-12 Armagh 2-8
Donegal and Tyrone will clash in next weeks Ulster U21 Football Final after wins on Wednesday night over Monaghan and Armagh.
The Donegal Monaghan game played in Omagh came to life in the final ten minutes of the first half with Donegal hitting 2-5 punishing the Farney men who were reduced to fourteen men.
Monaghan lost Conor Lavelle who received a red card having picked up a yellow and a black.
The Donegal goals in the opening half were scored by Jack O'Brien and Lorcan Connor.
Monaghan scored their goal ten minutes into the second half through Kevin Loughran.
When Ciaran Thompson scored Donegal's third goal it knocked the stuffing out of the opposition.
Downings Man Connor grabbed his second goal seven minutes from the end as Maxi Curran's side ran out comfortable winners.
In the other semi final played in Cavan Tyrone beat Armagh by four points.
Lee Brennan and Conor Meyler scored the Tyrone goals in the first half which built the foundation for the win.
A venue for the final has yet to be confirmed by the Ulster Council.