A ding dong five goal thriller ended with the unusual occurrence of an inform Peterhead defeat with Dumbarton moving into the next round thanks to some clinical finishing assisted by slackness in the home rearguard which sees them travel to Greenock Morton.
An open start to the cup tie saw Dumbarton earn an early corner kick which was confidently plucked out of the air by the home sides keeper Greg Fleming.
At the other end Peterhead broke clear down the left and a flashing cross from Aidan McIllduff was missed by all as it flashed across the penalty area with Jamie Stevenson retrieving the loose ball and fired a well struck shot low beyond the far post in the 6th minute.
It was the Sons who went in front after 13 minutes with the first shot on target of the game. A Dougie Hill free kick inside his own half seemed set to be easily grasped by Fleming but whether he lost the flight of the ball in the floodlights or simply list concentration, he fumbled his attempt at a catch and Callum Gallagher was on hand to net the loose ball for the cheapest of goals to concede.
The Blue Toon response was almost a spectacular equaliser, a Scott Brown rocket that fizzed a couple of yards over the crossbar.
Peterhead kept plugging away and deservedly levelled after 31 minutes. A Willie Gibson free kick was headed on by Russell McLean and gathered by Mason Robertson on the byeline to the right of goal.
He neatly cut the ball inside and Jason Brown sidefooted home from four yards out and the teams were all square.
Four minutes after the restart Peterhead should have gone in front. McLean broke forward muscling a couple of defenders out of his way in the process but his attempt to beat keeper Scott Gallacher failed as his shot was saved and out for a corner.
But they switched off in the 53rd minute as the Sons once again showed their clinical streak, Ian Russell cutting the ball back for Callum Gallacher to pick his spot and sidefoot just inside the left hand post from six yards.
Three minutes later it was all over, a David Wilson corner headed in by Gallacher from close range.
Three shots on target, three goals!
On came ace marksman Rory McAllister and he almost made an immediate impact sending a dipping volley centimetres over from the left side of the area.
The Blue Toon piled on the pressure trying to get themselves back into the game and Gallacher was a busy man denying McAllister with his leg then acrobatically diving salmon like to touch away a Gibson effort.
Eight minutes from time Balmoor erupted as a superbly flighted free kick by Gibson from the left wing found the diving head of a Mason Robertson and the difference was again just a single goal.
As the game drew to a close the Dumbarton goal led a charmed life and a David McCracken header was tipped over for another corner but for all their dominance it was just not to be for a Blue Toon side that were every bit the equal of their Championship opponents except where it mattered, in front of goal.
Peterhead Manager Jim McInally: “To be honest I thought we looked like the Championship team and the stats are astonishing. We’ve lost goals from two set pieces. We looked like we were going to score another goal then before you know it we are two goals behind. But I will tell you what, we have some gutsy boys in there and if it hadn’t been for the Dumbarton goalkeeper we would have won it.
“One of his saves was just unbelievable. Credit to our players and we deserved something out of the game.”