A control system for a work vehicle includes a power source with an engine and at least one motor configured to generate power; a transmission including a plurality of clutches configured for selective engagement to transfer the power to drive an output shaft of a powertrain of the work vehicle; and a controller coupled to the power source and the transmission. The controller has a processor and memory architecture configured to: initiate a transition for the transmission between a first transmission mode and a second transmission mode at a first shift point associated with an engine throttle shift function; determine a current engine speed; and generate and execute an engine speed command for the engine such that a commanded engine speed is a function of the current engine speed in accordance with the engine throttle shift function upon the transition of the transmission at the first shift point.