Annan grabbed a 2-1 stoppage-time victory over promotion-chasing Dumbarton thanks to Kevin Neilson`s strike.
Dumbarton almost took the lead after four minutes when Ian Chisholm ran clear on goal, but Annan goalkeeper Craig Summersgill got down quickly to make a brilliant save.
Chances were few and far between early on, but Annan almost made the breakthrough after 32 minutes when Jamie Dunbar headed Mike Jack's corner against the crossbar.
However, Annan deservedly took the lead three minutes before the break when Neilson nodded home a Jack corner.
Dumbarton levelled on the stroke of half-time when Ross Clark scored a penalty after he had been fouled by Steve Sloan.
Both sides had chances to win the match in the second half but Neilson nicked it with a 92nd-minute header - his seventh goal of the season.