The sedan's 4.7 litre V8 has been tuned to eke out a further 8kW, giving the nearly two-tonne performer a new 0-100km/h time of 5.0 seconds flat - a hair quicker than the previous 5.1-second official time.
Output for the big V8 is now rated at 331kW and 510Nm of torque - the latter being a result of improvements last year that focused on reducing internal friction.
Maserati's MC-Auto Shift transmission is also on-board, featuring steering-mounted paddle shifters and a quick-shifting Sports mode.
Despite the incremental power boost, fuel consumption remains unchanged at 15.7 l/100km - as does price, which stays put at $298,000 in Australia (plus on-roads).
Other items fitted as standard with the up-spec Sport GTS include 360mm front discs and six-piston Brembo calipers, low sports suspension and 20-inch light-alloy seven-spoke wheels.
If you've been considering Mazza's four-door, this edition will likely be the last call before an all-new model appears - likely at January's Detroit Auto Show.
Watch for more details on the new model in the coming months.