Despite falling behind after just seven minutes at The Rock, the Sons rallied to clinch a deserved 2-1 win over Arbroath and take a narrow advantage into Saturday's First Division play-off semi- final second leg at Gayfield.
Goals from Tony Wallace and Bryan Prunty cancelled out Stuart Malcolm's opener for the Red Lichties to leave Adamson's side within touching distance of a final berth against Ayr United or Airdrie, who drew 0-0.
The Sons boss said: "I am delighted. It typifies Dumbarton's season with the fighting spirit we showed.
"This team has got a terrific, never-say-die attitude. That is the fourth game in a row we have come back from a goal down to win the game.
"It was brilliant from the boys. But it is only half-time and we need to go again on Saturday."
The Second Division encounters between these two produced 21 goals over their four meetings and despite the potential prize on offer being far greater than just three points, neither team appeared to change their approach.
The opening exchanges were lively as both went in search of a crucial first-leg advantage.
With just seven minutes on the clock, the fifth fixture of the season had its first goal as Arbroath took the lead, with Malcolm rising highest at the back post to fire a bullet header beyond keeper Stephen Grindlay.
The early goal could have knocked Dumbarton's confidence but Adamson's side rallied in impressive fashion as they assumed the ascendancy and went in search of a quickfire reply.
It should have arrived after 10 minutes but keeper Darren Hill came to the visitors' rescue, denying Craig Dargo from point-blank range after the former St Mirren and Partick Thistle striker connected with Mark Gilhaney's teasing cross from the left flank.
The home crowd did not have to wait long to cheer, however, with Hill this time bound to be less than pleased with his efforts. A 30-yard drive from Scott Agnew seemed innocuous enough but the keeper could only parry it into the path of Wallace, who bundled the ball home from close range to give the Sons a deserved leveller.
It could have got better for Dumbarton before the interval, too, with Agnew again involved as his driving free kick hit Kieran McAnespie and clipped the top of Hill's bar.
Just after the hour mark, the turnaround in fortunes was complete for the Sons as they took the lead, albeit in controversial circumstances. Referee Craig Charleston ruled that a sliced clearance from Red Lichties defender Mark Baxter was a pass-back and awarded Dumbarton a free kick 16 yards from goal.
The decision incensed Paul Sheerin's men and the travelling support, with their mood not helped moments later as Prunty smashed the ball low into the net to put the hosts in the driving seat ahead of Saturday's second-leg shoot-out.
Adamson said: "It is only half-time. But what a great game of football it was.
"It was end-to-end stuff, there were goalmouth incidents and goals. I thought it was great."