To tinker with the lyrics of that traditional Scottish song; Dumbarton's run had not been so bonnie.

Well, things are looking a lot rosier now. Anchored to the foot of the first division with just five points heading into the final weekend of 2012, Ian Murray's resurgent side have romped into double figures and galvanised their survival bid.

Having signed off the old year with a 4-3 win at Falkirk last Saturday, the bottom dogs ushered in the new with a thumping victory over top dogs Morton. It was a thoroughly deserved triumph, thanks to a performance full of spirit, discipline, determined tackling and clinical finishing. For the lofty hosts, with just one defeat in their previous 18 league and cup matches, this was a bitter comedown. Had they taken a couple of first-half chances yesterday, though, things may have been different.

"Dumbarton are fighting at the bottom more than we were fighting to stay at the top and that's what annoyed me," seethed Alan Moore, the Morton manager. "We let ourselves down. How we can go from what we have done in the last 10 weeks to what we did today? I'm flabbergasted."

The swirling wind, relentless drizzle and skitey pitch was always going to make proceedings treacherous and Morton almost benefited from the conditions early on when a diagonal punt skidded through to David O'Brien, only for Jamie Ewings to dart from his line and smother the danger.

The Dumbarton goalkeeper would earn his salt again on 20 minutes as Morton tried to prise an opening. Having saved Scott Taggart's fierce effort, Ewings somehow managed to stretch out a hand and turn Peter Weatherson's follow-up poke past the post.

The visitors were holding their own but they should have been punished for a moment of madness on the half hour. Nicky Devlin's calamitous pass-back sent Weatherson clear but, as the advancing Ewings slipped, the Morton poacher sent his attempted chip woefully wide.

Dumbarton then hit them with a double whammy. In the 32nd minute, a patient, considered move ended with Garry Fleming swivelling on the edge of the box to unleash a low drive which zipped into the bottom corner. Seven minutes later, Jim Lister burst into the box and, after his low cross was partially blocked, Scott Agnew pounced.

Morton's pick-me-up should have arrived five minutes after the resumption. Substitute Peter MacDonald sent in a thunderous free-kick that was fumbled by Ewings but, with the goal at his mercy, the on-rushing Kevin Rutkiewicz jabbed wide. Fouad Bachirou then rattled the crossbar with a searing effort.

When Bryan Prunty rifled in a third, a dismal day for the hosts was completed. It was delight for Dumbarton, though. "It's a great win and I think that teams at the bottom may be looking over their shoulders now," said manager Murray.