How to make Torso face mouse, while only rotating on Y axis?

I don't want the character to be able to fall or anything, so I only want the torso rotated on the Y axis. How exactly would I go about doing this?

c.Torso.CFrame = CFrame.new(c.Torso.Position, Vector3.new(0,mouse.Hit.p.Y,0))

-- c being Character

Just makes the torso face upward and the character falls on its back.