Speed merchant Capuozzo has developed a reputation as one of the world's best finishers since his international debut last year and delighted the Saint-Etienne crowd with his 55th-minute effort.
Capuozzo, who plys his trade in France with Toulouse, exchanged passes with Monty Ioane before he dived over the line in a rare opportunity to stretch his legs in a bonus-point win for Italy.
Namibia opened the scoring at Stade Geoffroy Guichard when fly-half Tiaan Swanepoel sent over an early penalty but it was not the beginning of a shock win for the African nation.
It had been a similar story in their World Cup clash in 2019, where Namibia got on the scoreboard first before they succumbed to a 47-22 loss.
Kieran Crowley's Italy quickly responded with Tommaso Allan kicking his own successful penalty before number eight Lorenzo Cannone crashed over after 12 minutes.
Namibia hooker Torsten van Jaarsveld had been sin-binned in the play before after a collapsed maul and from the resulting penalty Italy grabbed the first of seven tries.
Allan added the extras and produced another conversion after quarter of an hour when Paolo Garbisi waltzed through the Namibia defence after a poor line-out.
There was a moment for Namibia, stripped in blue, to savour when Swanepoel's fine pass found wing Gerswin Mouton, who raced over in the corner for a fantastic try.
— ITV Rugby (@ITVRugby) September 9, 2023
It remained 17-8 to Italy at the interval before Crowley's men improved after the restart with Dino Lamb able to jot down after being carried over by his team-mates.
All eyes were then on Capuozzo, who ran inside before he traded passes with Ioane and showed his predatory finishing skills by wheeling over to score his first World Cup try.
With the bonus-point secured, Italy started to play with more freedom in the final quarter and Epalahame Faiva, Manuel Zuliani and Paolo Odogwu grabbed tries during the latter stages of the clash to ensure the tier one nation made a strong start to their campaign.