Aberdeen were defeated 2-0 by Livingston at Pittodrie to continue their disappointing Premiership form.
The Dons have now won just two of their last nine Premiership fixtures and drop to fourth in league table after Hibs win at St Mirren.
A mistake from Joe Lewis gave the Lions their first when he fumbled in Julien Serrano’s cross and poor defending handed them a second through Nicky Devlin.
Derek McInnes handed new signing Fraser Hornby his first start following the 21-year-old’s deadline day loan move from Reims.
Hornby replaced Matty Kennedy in the Aberdeen line-up, while fellow deadline day addition – St Johnstone forward Callum Hendry – started on the bench.
Aberdeen made the worst possible start falling behind in the seventh minute with captain Joe Lewis at fault.
The move started with Greg Leigh sloppily conceding possession inside the Dons’ half which led to Jason Holt eventually feeding Julien Serrano on the left flank.
Serrano’s cross to the near post looked relatively straightforward for Lewis to deal with, but the captain fumbled the ball into the net.
Six minutes after falling behind Aberdeen lost one of their main creative forces, with Ryan Hedges forced off with a suspected shoulder problem after landing awkwardly in the early stages.
Despite treatment the Welsh international was unable to continue and Matty Kennedy replaced him.
An just after the quarter hour mark Livi doubled their lead. The Lions kept the pressure up following a corner and when Josh Mullin crossed from the right side Nicky Devlin was given the freedom of the penalty area to plant a header beyond Lewis.
After racing into a two-goal lead Livingston were in control of the game and they made it difficult for Aberdeen by being disciplined within their shape, which meant the Dons found it difficult to break them down.
The visitors were also a threat on the counter-attack with Jay Emmanuel-Thomas sending a low strike narrowly wide following on promising raid forward.
Aberdeen’s first moment of threat came just before the half hour mark when Ash Taylor’s header from a Lewis Ferguson free-kick was easily gathered by goalkeeper Max Stryjek.
The Dons suffered another injury before half-time with Taylor having to be replaced by Dean Campbell and Connor McLennan was also withdrawn and Callum Hendry handed his debut.
These changes led to a change of shape to 3-5-2 in a bid to change the momentum of the encounter.
Eight minutes into the second period Aberdeen were close to pulling a goal back with Ferguson’s snapshot from inside the area deflecting onto the underside of the bar and bouncing down, but video footage appeared to show that it hadn’t crossed the line.
Ferguson test Stryjek soon after with a drive from 20 yards.
Aberdeen continued to pen Livingston in, but for all the crosses slung into the box a comeback never looked likely and the visitors could have added another with Scott Pittman’s low effort hitting the left post in the closing stages.
Aberdeen: Joe Lewis, Tommie Hoban, Ash Taylor (Dean Campbell 43), Andy Considine, Greg Leigh, Lewis Ferguson, Ross McCrorie, Connor McLennan (Callum Hendry 43), Ryan Hedges (Matty Kennedy 14), Jonny Hayes, Fraser Hornby (Niall McGinn 75).
Subs not used: Gary Woods, Shay Logan, Dylan McGeouch, Miko Virtanen, Jack MacKenzie.
Livingston: Max Stryjeck, Nicky Devlin, Efe Ambrose, Aaron Taylor-Sinclair, Jackson Longridge, Steve Lawson, Jason Holt, Josh Mullin (Scott Robinson 80), Julien Serrano, Scott Pittman, Jay Emmanuel-Thomas (Gavin Relly 69).
Subs not used: Robby McCrorie, Jack McMillan, Marvin Bartley, Alan Forrest, Jaze Kabia.