The teeming rain didn't affect Fiji's running game, which proved far too strong for a Georgia side hoping to seal third place in Pool D with a win, which would have ensured automatic qualification for the 2023 World Cup.
Instead, Fiji have moved ahead of Georgia and provisionally over Australia into second place.
Fiji are still to face group leaders Wales and Georgia are up against two-time champions Australia, who have played one game less than Fiji.
As the rain poured down at Hanazono Rugby Stadium on the outskirts of Osaka, Fiji failed initially to capitalise on a bright start.
But it was a sign of things to come when Waisea Nayacalevu's spectacular first try put Fiji ahead midway through a rain-soaked first half where Georgia's Soso Matiashvili missed one penalty goal and slotted over another to make it 7-3 at the break.
Then the tries came thick and fast - one from Georgia's veteran flanker Mamuka Gorgodze, and then six from the flying Fijians who thrilled the crowd with one-handed passes and some spectacular running.
Left winger Semi Radradra scored two tries, with the other four coming from scrum-half Frank Lomani, right winger Josua Tuisova, flanker Semi Kunatani and replacement lock Api Ratuniyarawa.
With Fiji's forwards as slick as the backs, Georgia were simply overwhelmed. In the first half the scrums were evenly contested, with Georgia getting the upper hand at times.
Following a high Fiji tackle in the 15th minute, Matiashvili took the penalty goal from about 30 metres out wide on the right. The flag went up, then down, and three Georgia points were rubbed off the scoreboard.
Minutes later, a moment of typical Fiji improvisation caught Georgia cold as Radradra did well to stop fly-half Ben Volavola's grubber kick going out.
He showed good hands to feed the ball quickly and accurately inside to the surging Nayacalevu, who sprinted clear.
Volavola slotted the first of his five conversions and was not needed for penalty goals, given the rampant mood Fiji were in after the sheer disappointment of losing their second group game to Uruguay in one of the tournament's big upsets so far.
This was far more like the Fiji side that led Australia at half-time in its opening game, although the Pacific Islanders ended up on the losing side in the match.
Nayacalevu should have had a second try in the first half after a superb passing move cut Georgia open, but he fumbled midfield partner Levani Botia's pass inside and admonished himself after tumbling face-first into the wet turf.
Georgia then launched a brilliant attack from deep in their own half, carving Fiji open at speed with some great handling.
After left winger Alexander Todua and scrum-half Vasil Lobzhanidze were held up, lock Konstantine Mikautadze emerged through a scrum but knocked-on with the tryline in sight.
Todua had been high tackled near the neck area, however, and Matiashvili kicked the penalty goal to make it 7-3.
The teams traded tries early in the second half, and then it was time for the crowd to sit back and enjoy 30 minutes of the Fiji show.