Goals in either half were enough to end a run of three games without a win while the visitors' misery was compounded by Hugh Murray's late red card.
Ian Murray, the Dumbarton manager, was forced to miss the match after his wife gave birth to a baby boy earlier in the day. He would surely have failed to recognise his normally attack-minded side in the opening stages as Falkirk, bidding for a title lifeline, dominated.
There was some respite for the visitors when Mark Gilhaney sent in a dangerous cross at the other end but Will Vaulks headed clear with Chris Kane ready to pounce.
But play was quickly back at the other end where a series of corners finally brought the reward Falkirk deserved.
Mark Millar's delivery into the box caused problems for the Dumbarton defence and David McCracken got the final touch beyond the keeper.
Scott Agnew nearly caught Michael McGovern out on 48 minutes when spotted the Falkirk keeper off his line.
Agnew fired in a low drive from the left of the box with the goalkeeper clutching the ball on the line beside his left post. Loy then miscued wide with a header from eight yards out after a Vaulks cross.
Dumbarton had a spell of pressure, forcing a couple of corners, and Vaulks headed over from a dangerous Agnew cross. But Loy gave Falkirk some breathing space by sidefooting home after a Conor McGrandles pass.
Dumbarton's evening hit rock bottom when Murray was sent off for a second yellow in the dying seconds.