In control from the opening minutes, the clash was over as a contest inside a quarter of an hour. The scoring deluge continued throughout, Wales running riot as it crossed for seven tries in an emphatic bonus-point triumph.
Dan Biggar booted Wales into a third-minute lead after an Italy infringement at the breakdown.
Luca Bigi was then sin-binned for offside and Wales took immediate advantage from the scrum, Biggar's long pass finding Josh Adams, who surged over in the left-hand corner.
Biggar converted from the sideline but was errant from the tee after Taulupe Faletau strolled over on the opposite wing with the Italy defence stretched, making it 15-0.
Ken Owens drove over from a rolling maul, Biggar rediscovering his form with the boot in converting, and the hooker crossed again from close range for his second, in the process clinching the try-scoring bonus after 30 minutes.
Louis Rees-Zammit saw a try chalked off for a forward pass, but there was no denying George North as he sprinted in under the sticks after a neat offload from Jonathan Davies.
Monty Ioane provided something for Italy to cheer, collecting his own chip down the left wing and dotting down for a try that Paolo Garbisi converted.
Adams missed out on a double as he failed to ground the ball properly but, after Marco Riccioni was yellow carded for foul play, Callum Sheedy crossed for his first Wales try.
Rees-Zammit's interception try added further gloss to the final scoreline, and Wales will hope to display the same kind of ruthlessness in their decisive encounter in Saint-Denis.