Shaky Celtic continue to live on the edge as Hearts reeled in and Rangers hurdled after bench SOS

This was Celtic's game in hand over title rivals Hearts and Rangers and was bracketed into the must-win category if they are to successfully defend their crown. They made heavy weather of this match in stages but headed back down the A90 with the full loot after prevailing 2-1.

Nygren came off the bench on 60 minutes and seven minutes later he provided the magic touch to land Celtic the winner. The visitors had taken an early lead through Kieran Tierney, but were pegged back by a Kevin Nisbet penalty and at times looked shaky when the scores were level.

As it is, job done for Martin O'Neill's men. Celtic now move into second place in the league standings, five behind leaders Hearts. They leapfrog Rangers and are a point clear of them. Nine rounds of fixtures. The focus now turns to Ibrox, their second trip across Glasgow in a week, for their Scottish Cup quarter-final on Sunday.

This defeat condemned Aberdeen to bottom-six football for the second time in three seasons. Their miserable league form goes on, now with just one win in 13 top-flight matches. They are eight points clear of the relegation play-off places and will want to arrest such a slump before the split.

They are also still without a manager. Potential candidate Sandro Schwarz, wrapped up against the north-east chill and sporting a beige thermal hat, watched on from the Pittodrie Main Stand. Chairman Dave Cormack said on the eve of the match that the club will not rush an appointment. Caretaker boss Peter Leven will lead them into Saturday evening's Scottish Cup quarter-final away at Championship side Dunfermline Athletic, which looks an awkward assignment.

Celtic were forced into a change just before kick off when centre-half Dane Murray pulled up injured. Brentford loanee Benjamin Arthur was summoned from the bench for his first start and only his second appearance since moving north. The even lesser-spotted Joel Mvuka made up the substitutes.

Celtic didn't take long to find their stride. Their opener came on five minutes. Tierney scored it but the assist was the thing of beauty here. Luke McCowan's corner was acrobatically hooked on by Liam Scales - not known for his suppleness in the opposition box - and Tierney darted in unmarked to prod home from close range past helpless Aberdeen goalkeeper Dimitar Mitov.

A feeling of dread swept through the home crowd at Pittodrie. They've seen their team take plenty of beatings from Celtic over the years and the visitors spent the next five minutes zipping the ball about, but without finding much cutting edge.

An overhit cross from Aberdeen full-back Alexander Jensen required turning over the bar by Viljami Sinisalo but that changed the flow of the game. The Dons grew into it more and were awarded the chance to level from the penalty when Liam Scales kicked through the back of Toyosi Olusanya. It was a clear foul and Nisbet sent Sinisalo the wrong way to level.

The equaliser gave Aberdeen belief and their midfield, driven on by Rangers loanee Lyall Cameron, started to compete better with Celtic. Nevertheless, clear-cut chances were few and far between at either end. Sebastian Tounekti slashed a shot into the side netting and a couple of other efforts were blocked.

In first-half stoppage time, Celtic claimed for a penalty when Tounekti's cross struck the arm of Aberdeen defender Jack Milne. VAR Chris Graham took a look at it and decided it was not worthy of review. We went into the break all square.

Parity was so nearly ended just a couple of minutes into the second half when Mitchel Frame's accurate cross was headed goalwards by Nisbet. The ball seemed to be arcing into the top corner but Sinisalo leapt across and turned it over the bar. It was a stunning save.

The second half had more tempo about it. Tounekti nearly got in behind the Aberdeen defence; at the other end, Milne sliced the ball over the bar from a promising position, albeit nose-bleed territory for a centre-half. The final half-hour was set up to be of the grandstand variety. Celtic needed a goal.

O'Neill turned to Daizen Maeda and Nygren - two eye-catching omissions from the starting XI - as they replaced the largely ineffective Tomas Cvancara and McCowan. Nygren, with 18 goals to his name before the match, was the great hope. Aberdeen boss Peter Leven also twisted, taking off Olusanya for Kenan Bilalovic.

Of course, it was going to be the Swede. Not Bilalovic, but Nygren. It took just seven minutes for him to make an impact. Julian Araujo slipped James Forrest in down the right and his cross was guided into the net by the 24-year-old. The goal survived a VAR check, with the Celtic man onside by the merest of fractions.

Not that he or the Celtic fans cared. They were back in front. Now it was all about seeing it out.

Maeda could have made life a whole lot easier for the champions on 71 minutes when the rapid Japanese forward pounced on a Milne slip. But in keeping with his composure throughout this season, he dragged his shot harmlessly wide of Mitov's goal.

Celtic were now in the clear ascendancy but with only a one-goal advantage, they weren't comfortable. Marcelo Saracchi blazed another good chance over the bar. In stoppage time, Hatate caused a scare with a rash tackle that didn't connect with Cameron in the box. They continue to live on the edge.