In the Dons' last home game of the season, manager Steve Paterson handed a first-team debut to youth team player Scott Morrison, with fellow youth players Kevin Souter and Richard Foster finding places on the bench.
Partick came north looking for a clean sweep of wins against Aberdeen this season, having won their three previous encounters.
John Lambie's side remained unchanged after last week's defeat at Livingston, with former Dons Derek Whyte, David Rowson, Jamie Buchan and David Lilley starting for the visitors.
Thistle went ahead from the penalty spot in the 15th minute when Alex Burns easily converted after Steven Tosh had needlessly felled Jamie Mitchell inside the area.
At the other end Paul Sheerin picked up a loose ball and the midfielder had only one thought in mind as his 25-yard drive flew just over the crossbar.
After a period of dull play with neither side showing any incentive to create chances it was the home side who again came close to scoring, Leigh Hinds turning away from his marker to fire in a left-foot shot which went just wide with Kenny Arthur beaten.
Disaster struck for Thistle just after the re-start. Alan Archibald's backpass to Arthur was woefully short and Hinds nipped in ahead of the keeper before gleefully stroking the ball home from eight yards.
The Dons' perseverance paid off in the 63rd minute when Phil McGuire poked the ball home from six yards after Arthur had failed to hold a thunderous Sheerin drive.
More good play from the home side involving Hinds and Sheerin saw the latter's cross find the head of Stephen Payne, but the youngster's effort went just wide of the upright.
Sheerin almost added a third in the 75th minute when he delightfully pulled the ball away from Whyte before chipping the ball towards the top left-hand corner. However, Arthur somehow managed to get his hand to the ball and turn it around the post.
Thistle nearly drew level as the game went into stoppage time, but Stephen Craigan snatched at his shot from inside the area over the bar when under pressure from Kevin McNaughton.