Winger Ollie Sleightholme scored a hat-trick as the Saints ran in 14 tries in total against a Gloucester side that made 12 changes to their Challenge Cup semi-final win against Treviso last week.
Northampton took full advantage for a margin of victory that is only surpassed in Premiership history by Richmond's 106-12 victory against Bedford in 1999.
Curtis Langdon and Sam Matavesi scored two tries each, while George Furbank, Fraser Dingwall, Alex Mitchell, Alex Waller, Emmanuel Iyogun, Alex Moon and Tom James also touched down.
Saints move five points clear of third-placed Bath, who they face next weekend in the final round of regular season fixtures.
However, even a five-point win for Bath could not overturn Northampton as they have won two more matches.
"It's never nice to be on the end of a 90-0 humping but, at the same time, we had a job to do," said Northampton director of rugby Phil Dowson.
"I wanted to push the players to stay really focused on what that was and not get too distracted by the scoreline."
Saracens made sure of their place in the playoffs with a 41-20 win at Bristol.
The visitors overcame an early 10-0 deficit and a period with 13 men after yellow cards for England internationals Maro Itoje and Ben Earl to run out convincing winners.
Before being sent to the sin-bin in the second half, Itoje scored two of Saracens' four tries to secure the bonus point that helped lift them into second place.
"We didn't start the game very well and I'm really proud of the way we fought back to wrestle the momentum away from them," said Saracens director of rugby Mark McCall.
"We handled the 13-man period exceptionally by making a lot of smart decisions."
Defeat puts a major dent in the Bears' hopes of climbing into the top four as they slip to seventh.
Champions Cup semi-finalists Harlequins' hopes of a top-four finish are hanging by a thread after a 58-26 defeat at Exeter.
England wing Immanuel Feyi-Waboso shone for the Chiefs, who move above Quins into fifth in the table.
Exeter trailed 21-14 after 36 minutes but hit back in spectacular fashion with 44 unanswered points.
But a last-minute try by Italian international Louis Lynagh did at least earn Harlequins a four-try bonus point to remain in contention for the playoffs.
Fourth-placed Sale have their playoff destiny in their own hands when they visit Saracens on the final weekend of the season.
However, defeat would give Exeter, Harlequins or Bristol the chance to climb into the top four.
