A second-half turnaround by Dumbarton saw Falkirk go down 2-1 at the Bet Butler Stadium and slip further away from leaders Dundee.
The league's second top scorer Rory Loy opened the scoring for the Bairns as Mark Beck provided Loy to tuck away his 14th goal of the campaign shortly before the half-hour mark.
The visitors nearly doubled their lead moments later as Stephen Grindlay parried Beck's close-range header and the follow-up was put wide.
Michael McGovern was busy in the visitors' goal as he saved Scott Agnew's shot and Mitchel Megginson followed it up with a volley, which was deflected wide.
Megginson soon found the net as he sent Colin Nish's ball into the top left of Falkirk's goal to level and Jordan Kirkpatrick completed a quick turnaround for the Sons as he fired past McGovern from the edge of the penalty box with nearly 20 minutes remaining.