Abstract: A coupler latch mechanism is disclosed having a self-opening hook-up feature for facilitating the hook-up of an implement to the hitch on a tractor. The coupler latch mechanism includes a latch bar pivotally connected to a coupler frame immediately above a hook. A trigger member is pivotally connected to a midsection of this latch bar and has a downwardly projecting finger which is located rearward of the lower portion of the latch bar. The forward end of the trigger member is pivotally connected to a link, which is in turn pivotally connected to the frame. The point of attachment of the trigger member to the link is also the point of attachment of the trigger member to a vertical rod, which extends up through the frame. The upper end of the rod is pivotally attached to a lever pivotally connected to the frame. The control latch mechanism is able to open as an implement hitch pin presses against the finger of the trigger member.