Bill Mehmet notched a hat-trick for Saints to sink sorry Dumbarton
St Mirren displayed the kind of goalscoring form that has deserted them in the SPL to breeze into the third round of the Co-op Insurance Cup.
Stephen Robb opened the scoring on 18 minutes, Billy Mehmet made it two on 33 minutes and Andy Dorman put the Buddies on easy street before the break.
Mehmet completed his hat-trick with a quick-fire second-half double.
Craig Dargo and Gary Mason made it a magnificent seven for the Buddies with two further goals in the final quarter.
Surprisingly, given the gulf between the two sides, it took a while for the SPL outfit to impose themselves on their Second Division opponents.
Mehmet had a couple of efforts, one high and wide from distance, the other trundling in the arms of David McEwan from 16 yards out.
However, following the first of several impressive first-half passages of play, Mehmet split the Dumbarton defence allowing Robb to speed through the centre and dispatch his shot past McEwan from the edge of the box.
In the 22nd minute, Mehmet should have got on the scoresheet himself when he took a Franco Miranda pass in his stride 16 yards from goal but fired his angled hot wide of the far post.
Ten minutes later Mehmet grabbed the home side's second with a close-range rive after Dumbarton defender Michael O'Byrne made a mess of clearing a Miranda cross from the left.
Dumbarton were all over the place at the back and six minutes from the interval Dorman worked a clever one-two with Hamilton before dinking over McEwan from 12 yards.
The second half offered little respite for the bedraggled visitors.
Five minutes after the break, Mehmet grabbed his second when he turned O'Byrne just outside the six-yard box and slotted Hamilton's pass home.
Within two minutes he had completed his hat-trick, heading Garry Brady's cross past the helpless McEwen.
Dargo replaced Hamilton, with Wyness on for Mehmet, and the traffic continued towards the Dumbarton goal.
In the 70th minute, in the face of constant pressure, McEwen pulled off a fine save down at his left-hand side from Wyness' low drive.
But Saints were not to be denied, with Dargo and Mason stretching their lead further within a two-minute spell as Dumbarton imploded.
St Mirren manager Gus MacPherson:
"Last season was highly embarrassing and we mentioned it before the game but the important thing is to play the way you can and we did that.
"It is important in cup ties when you play lower league opposition that you score early.
"That releases the pressure because the pressure is on you, no matter what people say.
"When you go out, there is pressure to perform but I don't think we can have any complaints, we performed."
Dumbarton manager Jim Chapman:
"It sounds morbid but I enjoyed watching Saints play. Unfortunately, it was against my team.
"Their movement and application was brilliant and we got ripped to bits.
"We are all gutted and the players are hurting but if we can learn from that then we can do all right at our level."
St Mirren: Howard, Ross, Miranda, Haining, Potter, Mason, Dorman (Murray 73), Brady, Robb, Mehmet (Wyness 58), Hamilton (Dargo 57). Subs Not Used: Cuthbert, Smith.
Goals: Robb 18, Mehmet 33, Dorman 39, Mehmet 50, 52, Dargo 75, Mason 77.
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