EVEN when Celtic are winning titles under Ronny Deila they fail to convince entirely.

This 3-2 win over their nearest rivals Aberdeen at Parkhead yesterday sent them 14 points clear at the top of the Ladbrokes Premiership with two games remaining and finally clinched their fifth consecutive triumph.

But, as has so often been the case during Deila’s two years in charge in Glasgow, there was just as much on show to infuriate their supporters as there was to delight them during the course of 90 eventful minutes.

Celtic had romped into a seemingly commanding three goal lead courtesy of a first half Patrick Roberts double and a Mikael Lustig strike early in the second and the crowd got ready to party in the sunshine.

The arrival of Efe Ambrose on the park at the start of the second half, though, coincided with a revival by the visitors. A Niall McGinn strike and an Andrew Considine header put a different complexion on proceedings.

Ultimately, Celtic held on to triumph both in the match and the league. But this match was Ronny Deila’s tenure in microcosm; there was some stylish play to enjoy and silverware was duly secured, but, in the process, a fragility was evident which concerned their followers.

Adam Rooney, Aberdeen’s top scorer this season with 20 goals, was missing due to a recurrence of the thigh problem which has sidelined him for three months of the 2015/16 campaign. His absence was noticeable in the fifth minute when the visitors created the first scoring chance of the match.

Jonny Hayes’ tenacity on the left enabled him to square the ball into the Celtic six yard box. But McGinn shot wide of goal against his former club. Would their first choice striker have squandered such a dangerous ball?

If McGinn had converted so early on it may have been an altogether different game. Aberdeen could have sat back and protected their lead. As it was, they fell behind just two minutes later.

Lustig fed Roberts on the right flank and the winger took the ball on a mazy run before cutting inside. Despite the close attentions of Graeme Shinnie, he was able to unleash a left foot shot away from fully 25 yards out which sailed past Adam Collin and into the top left corner.

The English teenager cost City £12 million from Fulham last summer. It has, despite his glaring miss against Rangers in the William Hill Scottish Cup semi-final last month, looked to be money well spent since he moved to Scotland on loan back in January. He netted his second in the 20th minute.

Leigh Griffiths teed him up with a shot in the Aberdeen box with a cheeky dink underneath Considine. His team mate curled another sublime left foot effort beyond the clutches of the outstretched Collin.

Simon Church, the Wales striker, limped off injured three minutes before half-time and was replaced by Mark Reynolds, a centre half, as McInnes shuffled his line-up. It seemed to end what little hope Aberdeen had of taking another from the game.

Yet, when Ambrose took to the field at the start of the second half – the error-prone Nigerian replaced from captain Charlie Mulgrew in the heart of the Celtic backline – you knew that anything was possible. So it proved.

The champions elect forged three in front in the 49th minute following some fine work by Callum McGregor down the right. He skipped past Shinnie, burst into the Aberdeen box and cut the ball back to Lustig who made no mistake.

But when Ambrose gifted Hayes possession shortly afterwards it was an indication the outcome of the game wasn’t a foregone conclusion after all. Aberdeen nearly pulled one back. The Irishman charged upfield and Craig Gordon did well to deny his shot.

Ambrose failed to close down Hayes once again in the 58th minutes and he supplied McGinn who had the simplest of task to stroke past Gordon. The scorer turned provider six minutes later when he picked out Considine with a free-kick which Ambrose had conceded and watched as the defender headed home.

Ambrose is a pleasant fellow and a popular member of the Celtic squad. He does fantastic somersaults during post-match celebrations. But one of the first act of Deila’s replacement should be to move him on. He is too much of a liability defensively and has been for some time.

But the Norwegian, who has announced he will stand down as manager at the end of the season, was entitled to enjoy the moment with his players as their ultimate objective was, after a slight second half scare, secured.

“I think we were very consistent in our results," said Deila. "We haven’t lost in the league since February even though we have felt like it was going to be relegation this year!

"It is a special atmosphere and feeling to sit here. But we are the best and the biggest club and everything you achieve here is ‘normal’. So the demands are high. It is important to enjoy it and in the end I think the fans were happy to get the championship.”