Here are my Donomite predictions. I don't remember the trainer's names so I will just list the pokemon.
Seismitoad vs Sawk - Confirmed
Gothita vs Pansage - Confirmed
Simisage vs Scraggy - Confirmed
Dewott vs Excadrill - Cause Iris won the last one I think she'll bomb here.
Simipour vs Simisear - Basically confirmed
Druddigon vs Bisharp - Confirmed
Throh vs Meinshao - Built up on Pokemon Smash as a character of significance, so I think he will advance.
Conkledurr vs Emboar - Confirmed
Scraggy vs Pansage - Proves Scraggy's strength and development
Dewott vs Simipour - Allows Burgundy to advance further than Cilan, showing her to be a worthy rival
Emboar vs Bisharp - Very close match, show's off Bisharp's power by overcoming double disadvantage, as well as Bianca's need to further develop as a trainer now that she has powerful pokemon.
Throh vs Sawk - Awesome combat match, I predict will be my favourite of the entire BW series. Throh narrowly winning.
Bisharp vs Dewott - Burgundy gets cocky due to getting futher than Cilan, after providing a bad tasting, she is swiftly beaten. Forcing her to rethink her current methods.
Scraggy vs Throh - I honestly couldn't think of a fesible way for Ash to reach the finals, so the next best thing would be to lose to the eventual winner.
Bisharp vs Throh - Throh's trainer asserts himself as a powerful trainer and hopefully a league rival for Ash.