Rangers slumped seven points behind Celtic in the title race after a 3-1 defeat to Aberdeen at Ibrox.

Defender Stefan Gartenmann opened the scoring with a first-half header from a corner, exploiting Rangers' weakness from set-pieces, before Jamie McGrath slammed home with 20 minutes to go after a failure to deal with another set-piece. Rangers mounted a late rally with Abdallah Sima scoring with 15 minutes to go but the equaliser was to prove elusive and Jamie MacKenzie's late strike put the game to bed.

To compound matters for beleagured Ibrox boss Michael Beale, Scott Wright was sent off for a second bookable defence after coming on as a second half substitute, meaning we will be suspended for the next game against St Mirren.

The win was a tactical triumph for Aberdeen manager Barry Robson who set his stall out to hit on the break and his team followed his guidance to the letter.

The final whistle was met with a chorus of booing by the few fans remaining in the stadium as the Ibrox club's title challenge was left on life support after just seven games.

Here are the key taking points from the match.

Beale's tenure surely in final stages

The manager's failure to win the big games has come together with clear recruitment problems to create a perfect storm. Dropping so far behind Celtic at this early stage of the season is a terrible situation given the amount of money available to reshape the squad in the summer. The board backed the Englishman but he's not been able to encourage his players to deliver. Most importantly, Beale has lost the fans who have strongly indicated they no longer have faith in his tenure. The loss to Celtic at the start of the month ensured it was always going to be an uphill for the 42-year-old to win hearts and minds and today only further underlines the seriousness of the situation the football department now finds itself in. Rangers will surely opt to find a new manager before long.

Gritty Aberdeen execute manager's plan

The Dons started the game without flying winger Duk partnering the perennially dangerous Bojan Miovski in what was clearly a defensive minded change. Barry Robson set up with five at the back in an effort to hit Rangers in transition and it worked a treat as they dug in and did each other's dirty work as Rangers dominated the ball. They got a foothold when a rare corner yielded the opening goal from big defender Gartenmann who nodded home a simple header. They continued to look dangerous when given the sniff of a counter and nearly made it two with Miovski hitting the post with a header at the start of the second half. By the time of Jamie McGrath's second, the goal hardly came against the run of play. Robson will be delighted with the diligent and professional way his team executed the game plan.

Dessers struggles continue

The Nigerian striker continues to embody the failure of summer recruitment after a £4.5m move from Cremonese. He has scored three goals and assisted two since arriving in Scottish football but made little other positive impact. He lacks pace, seems born offside and hasn't shown the movement you'd expect of a striker the manager surely bought to bring 20 plus goals to the team. Not since the infamous Egil Ostenstad has a striker arrived promising so much but offering so little. In the opening moments he was put through on goal with a ball over the top. It was a difficult chance but a situation any striker would look to work the keeper in. Dessers could only blaze wildly over the bar. Rangers will have to hope that there's a form problem because if this is his level, it's nowhere near good enough.