WHAT we've come to expect from a Ronny Deila team at its best is that it will score and it will concede, which was demonstrated up to a point as an important win was delivered against the opponent likely to finish second in the SPFL Premiership.

Celtic have let in one goal in each of their last six games but here, for the first time in five, they had enough firepower to manage a couple of their own.

This was not Deila's Celtic at their best, or at least their supporters must hope it wasn't. They did enough to deserve a narrow win and the result lifted them to fourth - not too far behind Hamilton, now - but when captain Scott Brown ran out of steam on his return from injury the team lost its energy and control.

Aberdeen's strong spell in the second half yielded a revealing goal. Virgil van Dijk strolled imperiously through the afternoon and used the ball with his customary elegance, yet he switched off entirely and was blissfully unaware of David Goodwillie ghosting in behind him to convert a diving header. Van Dijk's concentration and awareness will need to be sharper in the Europa League on Thursday night.

In general Celtic defended more impressively than they had in dropping points at Dens Park in their previous game. The full-backs, Emilio Izaguirre and Efe Ambrose, were not so recklessly exposed and Van Dijk, Jason Denayer and Stefan Johansen were often held back to police Aberdeen as their team-mates attacked. Aberdeen's danger on the break was acknowledged and respected by Deila. Van Dijk and Denayer had the pace to snuff out a couple of dangerous moves and Craig Gordon's saves and handling were excellent.

They will face a stiff test against Red Bull Salzburg on Thursday night. Denayer was left out against Maribor because Deila felt he needed experience in the backline, but the 19-year-old will play this time given Charlie Mulgrew and Mikael Lustig's injuries. "I feel very good playing alongside Virgil," said Denayer.

"He speaks to me a lot. He is very calm. When he speaks, it is not aggressively. It is better to speak calmly, we understand each other better that way. Virgil is a very good player and I think he can play at the highest level. I'm very happy he stayed at the club.

"But Virgil and me are different. He is more experienced. I think we are getting close to how the manager wants us to play. In the first half against Aberdeen, we did very well. We need to train more now, we need time and we will be better."

Stefan Scepovic, Aleksandar Tonev and John Guidetti all made their debuts. Three new forwards, yet the most impressive attacker was the oldest, Kris Commons. Aberdeen never really handled Commons's movement and when no-one closed him down 20 seconds into the second half he took Callum McGregor's pass and struck a shot which Shay Logan deflected into the net.

Celtic's first goal was messy. Commons' corner bounced off Denayer and Logan in the goalmouth, was whacked back by Efe Ambrose and flew into the net via Denayer's hip and the crossbar. Guidetti, on for the last 30 minutes, looked brighter than Scepovic who got 60 and Tonev who saw 70. The Bulgarian didn't do much, although it turns out he may have done far too much. He has some explaining to do after Logan complained that he had directed a racist comment at him.

Otherwise, Commons' exploitation of space and directness made him a constant thorn for Aberdeen and that, with Brown's early dynamism, saw them over the line.

Aberdeen are down at ninth in the table having lost three of their first five games. They will rise. There was encouragement for them in Goodwillie managing a first goal in his sixth appearance. It's nearly three years since the 25-year-old scored against Spain for Scotland, and scored a handful in the Barclays Premier League for Blackburn Rovers.

He has nudged Adam Rooney out of the starting team but needs goals if he is to be the established first choice. "My confidence probably has taken a hit in the last year or two," he said. "To be at the top level, playing for your country against Spain, and then come sort of crashing down does hit you a bit.

"It's just games that will bring confidence and goals back for me. I'll take it one step at a time.

"Everyone has their ambitions and I'd obviously love to play for Scotland again. It's just a case of getting back on my feet again and trying to get sharp, to get back playing regularly and hopefully enjoy it more.

"The manager has got us believing that it doesn't matter what the score is, we can still go on and win the game. That showed today in the way we played after going 2-0 down. The players have that belief from the manager that we can get closer to Celtic this season. He tells us we can."

In a few months this fixture should be first against second. For now Celtic are not in the top three, nor Aberdeen the top eight.