Ards moved off the bottom of the Premiership after the newly promoted side secured their first league win.
It was a deserved victory although United dominated at Dixon Park before Ben Roy cut inside and smashed into the top corner after 32 minutes.
Alan Davidson squandered Ballymena's best chance when his tame shot from six yards was easily saved.
William Faulkner managed to find the net from near the corner flag on 79 minutes to double the advantage.
Ards grew in confidence after the opener and Paul McDowell's effort flew just over.
Alan Teggart was the dangerman for the visitors but they rarely threatened in a disappointing display.
Faulkner's speculative effort flew across the United goal before hitting the top corner.
"Everyone's buzzing - it is a great night for the club and my first win the Premiership," said Ards boss Niall Currie.
"The players were magnificent, especially in the second half, and Ben showed that he is a fantastic finisher and match-winner."