Prior to this game, Saints had only managed three home goals in the SPL this season, but Saturday's attacking display at Love Street showed signs of a growing confidence.
It was as slick a performance as St Mirren have delivered this season and they fully merited the the points.
Inverness boss Craig Brewster, who turned 42 on Saturday, will be in no mood for celebrating.
He and his Inverness side however look set for a long winter as they slipped nearer the foot of the table.
St Mirren manager Gus MacPherson sent out the same team that served him well last Saturday.
Looking to build on the valuable three points won at Falkirk, MacPherson remained faithful to the same starting XI.
Meanwhile, Brewster reintroduced 20-year-old striker Adam Rooney to his side, while Ross Tokely was still missing through suspension.
Prior to kick-off, a warm welcome was given to a travelling band of FC Mechelen supporters, who were paying homage to Love Street.
The Belgian club had played St Mirren in the European Cup Winners Cup in 1987 and fans came to say farewell to the soon to be defunct stadium.
Inverness started brightly, winning three corners inside the first six minutes.
Ian Black tested Mark Howard from distance but the closest the visitors came was when Douglas Imrie's cross-cum-shot brought out a fingertip save from Howard.
However, the home side settled and Jim Hamilton nearly caught out Ryan Esson with a speculative angled shot, but the keeper recovered and saved well.
After 16 minutes, St Mirren went ahead through Dorman, who picked up on a headed ball through from Dennis Wyness and ran into the box before coolly slotting under the body of Esson.
Two minutes earlier, Rooney had crossed to Andrew Barrowman but he failed to connect his header properly and the chance was gone. Minutes later, Rooney passed up another chance.
As the half came to a close, St Mirren were back in the ascendancy, with Brady and Hamilton seeing shots fly over the crossbar.
Inside the first minute of the second half, Brady scored to make it 2-0 to the Paisley club.
A cross from Hamilton was out of reach of all the Inverness defenders but Brady was on hand at the back post to knock it home from seven yards.
Stephen McGinn should put St Mirren three up but he spurned a chance from close range with the goal gaping.
Wyness had a better effort in the 57th minute but Howard stood strong, pushing the ball away.
In the 66th minute, Inverness tried to re-energise their team and brought on Roy McBain and Rory McAllister for Black and Barrowman.
Esson prevented Hamilton inflicting further damage with a save from his feet in 74th minute following a sweet moving involving Jack Ross and Wyness before Hamilton shot.
As the clock ticked down, the visitors replaced the frustrated Imrie with Zander Sutherland but St Mirren were more than comfortable in their two-goal lead.
Inverness keeper Esson required treatment following a clash with Wyness. The big keeper seemed dazed but played on.
Craig Dargo came on for Hamilton in the 85th minute.
With two minutes left of regulation time, he zinged a shot but Howard managed to parry before smothering the ball.
As the final whistled sounded, the St Mirren fans celebrated a fine performance, three points and their ascent up the SPL table.