St Mirren picked up a well-deserved first league win at Pittodrie since 2011 thanks to a double from Curtis Main and Declan Gallagher's first goal for Saints.
Deadline day signings Thierry Small and Tony Watt were named on the bench with Keanu Baccus returning to the starting line-up in place of Ethan Erhahon following the latter's move to Lincoln City. Other than that Saints remained unchanged from Saturday's 1-0 win over Motherwell.
The game got off to a dramatic start when Aberdeen were reduced to 10 men after just seven minutes following a VAR check. Ross McCrorie caught Charles Dunne with an elbow and was shown a red card after referee Grant Irvine's check at the monitor.
Saints were seeing the majority of the ball, but neither side really created anything in the opening 30 minutes, save for a blocked Alex Greive effort on 25 minutes. Matty Kennedy dragged an effort wide from the edge of the area on 32 minutes in what was the home side's first decent opportunity of the match.
The game sparked to life on 35 minutes when Dunne was late with his challenge on Aberdeen captain Graeme Shinnie and received a yellow card. The challenge caused tempers to fray with Duk, Ylber Ramadani and Greive all going into the book after a stramash.
Saints should have taken the lead on 38 minutes after good work from O'Hara saw the stand-in skipper drive into the box from the left-side and roll the ball into a dangerous area. Curtis Main slid in to get a toe to it with the goal gaping but knocked it agonisingly wide of the right-hand post.
Heading into the final five minutes of the second-half, Trevor Carson was called into action for the first time when he tipped over a cross from the left-side as it looked like it might creep under his bar.
Stephen Robinson made a change at the break with Declan Gallagher on to replace Dunne.
Saints were dominating possession and took the lead a little over 10 minutes into the second-half when Main scored his second goal in as many weeks. The forward was on hand at the front post to meet Strain's free-kick from the left and bulleted home a header to put us in-front.
Buoyed by the goal, the Buddies went in search of a second with Main twice having shots blocked inside the area while Baccus forced a brilliant save from Joe Lewis. With 20 minutes remaining it was Greg Kiltie who was agonisingly close to making it 2-0 was his header came off the bar and Strain's follow-up deflected wide by Shinnie.
Frustratingly, Aberdeen would get themselves level against the run of play on 74 minutes when Bojan Miovski scored from the penalty spot. Marcus Fraser was adjudged to have fouled Duk as the Aberdeen man broke into the box and referee Grant Irvine pointed to the spot with Miovski equalising.
Main put St Mirren back in front with nine minutes of normal time remaining with a super finish inside the box. The forward picked up a brilliant ball from Baccus and spun before brilliantly firing into the bottom corner.
The Buddies put the seal on the victory in stoppage time when Gallagher scored his first St Mirren goal. The defender rose highest to meet a Small corner and despite not initially being given, a VAR check confirmed it crossed the line and Saints ensured they'd be leaving Aberdeen with all the points.
Declan Gallagher scores the third in win over Aberdeen (Image: AFC Media)
Full-Time: Aberdeen 1-3 St Mirren
St Mirren: Carson, Fraser, Gogic, Dunne (Gallagher 46), Strain, Baccus, O'Hara (c), Kiltie (Flynn 90), Tanser (Small 76), Greive (Watt 72), Main
Subs Not Used: Urminsky, R.Taylor, Small, Flynn, F.Taylor, Jamieson, Offord
Aberdeen: Lewis, McCrorie, Pollock, MacDonald, Kennedy, Ramadani, Clarkson (Watkins 83), Shinnie, Hayes, Miovski, Duk (Markanday 83)
Subs Not Used: Ritchie, Barron, Myslovic, Coulson, Duncan, Bavidge, Roberts
Referee: Grant Irvine
Assistant Referee: Jonathan Bell
Assistant Referee: David Dunne
Fourth Official: Ross Hardie
VAR: Gavin Duncan
Assistant VAR: Graeme Leslie
Attendance: 13,014
