Lawrence Shankland's second-half penalty prevented pressure intensifying on manager Derek McInnes as Rangers edged out Aberdeen to earn their first Scottish Premiership victory of the season.

McInnes urged his side to respond at Pittodrie after a Conference League qualifying exit to Jablonec on Thursday denied his team European football for the season and continued his troubling start.

A mix of profligacy and a lack of quality looked like it would plague Rangers again, but a careless lunge from Dan Happe on Djeidi Gassama allowed captain Shankland to fire a spot-kick into the top-right corner.

The Ibrox boss and his players breathed a huge sigh of relief when an on-field review judged Kevin Nisbet to have pushed Dujon Sterling moments before the Aberdeen striker thought he had headed in a late equaliser.

Despite another unconvincing display, one positive for McInnes was the introduction of Kim Min-su, who impressed on his debut and provided something different in attack.

In the first half, the South Korean was denied by a last-ditch Lewis Mayo block before a goalline intervention from Afeez Aremu prevented Shankland converting the rebound.

In a game that turned chaotic in spells, Kim then had a fierce long-range free-kick tipped over the bar by goalkeeper Marius Muller before Shankland's decisive penalty.

Aberdeen failed to create for much of the contest but passed up two early opportunities when Happe failed to connect cleanly with a back-post attempt and Mitchy Ntelo forced Ivor Pandur down to his right.

Pre-match, Stephen Robinson spoke about "stability" and "continuity" after naming an unchanged side following Aberdeen's 3-0 League Cup last-16 win over Dundee last time out.

But this was a display that will have Dons fans still asking questions after another fluctuating performance.

Former Aberdeen defender Mark Reynolds mentioned a "lack of penetration" on BBC Sportsound, with Robinson's men ending the contest with their expected goals (xG) rating from open play at just 0.15.

They forced Rangers to panic at times, but this will feel like an opportunity missed. Over their three league matches, their total accumulated open-play xG stands at 0.71.

As well as Kim impressing on his debut following his arrival on Thursday, Gassama had one of his better Rangers performances more than a year after joining.

The winger threatened in the first half, along with Kim and fellow wideman Findlay Curtis, as McInnes' side responded to a shaky start.

Rangers were far from convincing, both with and without the ball, and McInnes will know there is still a mountain of work to get through.

But after a bruising week, he will hope the green shoots from a hard-fought win away to his former club can develop into more stable foundations.

Aberdeen boss Stephen Robinson: "I'm disappointed about the result of course. I didn't think there was a lot in the game. The key moments went against us and probably cost us the game - they cost us a point at least.

"If I give my thoughts [on the decisions] I'll get a five or six-match ban. [The players] showed better quality in the second half. The expectation was on Aberdeen to take the game to Rangers and I didn't think we did that well enough."

Rangers manager Derek McInnes: "Contrasting feelings from Thursday night. It was a tough few days for us all. I thought today we were far more like the Rangers team I want us to be.

"[Kim Min-su] coming in gives us a much-needed dose of quality. We've been searching for that for a while. We've waited a long time for him and been a bit frustrated we haven't got him in quicker.

"The best part for me was the competitiveness of the team was clear. We get our clean sheet and it was a deserved win."