Dumbarton made it three games without defeat with a 1-0 victory over East Fife on Saturday.
Kalvin Orsi hit the inside of the post in the first-half as Sons came closest to breaking the deadlock.
After the interval, the visitors had a golden chance to take the lead when they were awarded a penalty but Brett Long kept out Alex Ferguson’s effort.
Dumbarton found the breakthrough on 73 minutes when Martin McNiff turned inside the box and slotted into the net.
Sons had an opportunity from the spot of their own on 88 minutes but Stuart Carswell had his attempt saved by Allan Fleming.
The result ensures Stevie Farrell’s side will finish the cinch League Two season in second place with a spot in the play-offs now confirmed.
Goalkeeper Long also broke the record for most clean sheets kept in a season with the shutout being his 16th and surpassing the previous best of 15 that was set by Ian McFarlane.