Derek McInnes' side dominated proceedings and recorded back-to-back league wins thanks to a Paul Quinn own goal four minutes before the hour.
Adam Rooney went closest to opening the scoring in the first half as the visitors were frustrated, but when the striker's chance did come he failed to connect properly with his header and it drifted wide.
Aberdeen resumed their control after the break and eventually got their reward as the unfortunate Quinn fired beyond Mark Brown from six yards out.
A low cross from the right was aimed at Rooney, but Quinn sliced the ball into his own goal when trying to clear.
The visitors pushed for a second in the remaining 30 minutes, but Andrew Considine, Peter Pawlett and Jonathan Hayes all wasted chances to punish County further.
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