Jinky Hilton’s superb double helped Dumbarton make it back-to-back victories in League One.
The forward’s stunning first-half opener was cancelled out by Jake Davidson’s bullet header on the half hour, before a clinical Ryan Blair finish restored Sons’ lead.
And Hilton had the final word, drilling home from the edge of the area to move Stevie Farrell’s men 15 points clear of the Caley Jags – and to within five points of the League One summit.
Delighted boss Farrell said: “We were excellent from start to finish. The only disappointment is conceding the goal from a corner.
“We don’t give up many chances, Brett has had one really good save but not much else, and the structure going up the pitch was excellent. It was very, very good.
“Jinky Hilton is a player who tries things, he doesn’t care where he plays. He’s someone who backs himself so much. And Ryan Blair is composed, it would be easy to lash at it but he picks his spot.
“Dumbarton fans must be loving it because we’re magnificent to watch going forward. We’re such a threat. We’re so good to watch.”
Sons stuck with the same side that had recorded their first league victory of the season a week previous against Arbroath, whilst Inverness were forced into two changes from the team which had defeated Annan Athletic – with Wallace Duffy leaving the club after they entered administration, and illness ruling out Danny Devine.
With the wind at their back the Highlanders controlled possession in the early exchanges, albeit without calling Brett Long into any form of action.
And with 14 minutes played Sons made their first attack of the game count – in style.
Great play from Michael Ruth set up Jinky Hilton, and he let fly from outside the box – rifling high beyond the full stretch Musa Dibaga in the visitors’ goal.
Caley Thistle almost found an immediate response as Brett Long superbly denied Keith Bray from inside the six yard box, but the assistant’s flag was already raised.
That was a warning shot from the away side however, who levelled after controlling possession for much of the half.
Paul Allan’s wicked corner was met by the unchallenged head of Jake Davidson, who bulleted beyond Long.
Good forward play from Michael Ruth then set Matty Shiels clear, but he drilled at Dibaga.
At the other end a clever short corner routine ended with Robbie Thompson’s effort from the edge of the area being charged down by a cluster of white shirts.
Sons had the final opening of the first 45 as Mikey Miller’s cross found the lively Hilton, but he glanced wide of target.
The second-half started with more of the same, as the visitors looked the more dangerous.
Only a superb Brett Long save denied Billy McKay’s clever header from close range, in a chance that seemed to take the wind from the away side’s sails.
After growing into the game, Sons forced their first corner just after the hour – and made it count.
Ryan Blair’s swirling delivery caused panic at the back, with Mark Durnan and Michael Ruth returning the ball to the midfielder, who clinically stroked beyond Dibaga from a tight angle.
By this stage Dumbarton looked like a team enjoying themselves, with a striding run from Sena Niang sending substitute Finlay Gray clear – and Michael Ruth inches away from heading in a third.
Sons wouldn’t be denied for long however, with a third goal arriving with 20 minutes remaining.
Man of the Match Jinky Hilton drove forward from midfield and, as defenders backed off, drilled beyond Dibaga from the edge of the area.
A thunderous Joel Mumbongo effort then flashed over as Sons went in search of a fourth, before the visitors passed up two late openings.
First Davidson blazed over a Luis Longstaff corner, before Manchester United loanee James Nolan fired tamely at Brett Long from a good position in the area.