The centre-back was shown the marching off orders after he brought down speedster Zakaria Mumuni.
Toure opened the scoring in the 15th minute by connecting simply from Justice Blay’s cross.
The home side took control in the early stages but Emmanuel Ocran, Abdulai Ibrahim and Victor Oduro made it difficult for Medeama.
Dreams will feel they should have ended the game with at least a goal after putting up an impressive display at the Akoon Park.
Medeama coach Yaw Preko handed starts to Baba Abdulai Musah and Richard Boadu with Ibrahim Yaro deployed on the right.
Medeama struggled to command the midfield as largely expected after being curtailed by the visitors.
Zakaria Mumuni squeezed a free kick with a beauty, leaving the Dreams FC defence in tatters to allow Toure to tap home for the insurance goal.
Medeama move into the top four on the table with 30 points.
— Medeama SC (@MedeamaSC) April 11, 2021