Scotland confirmed their 2016 European Championship qualifying credentials with a hard-fought 1-0 win over Republic of Ireland thanks to a wonderful second-half strike by Shaun Maloney
Gordon Strachan's side had the best of a tense, frenetic first-half at Celtic Park but passed up a couple of good chances to take the lead.
The visitors came out rejuvenated after the break but Scotland regained control with Wigan forward Maloney, back on his old stomping ground, curling the ball past David Forde in the 75th minute with technique fit to win any game.
Scotland go level on seven points with Ireland and Germany, with Poland Group D leaders taking 10, but there are surely twists and turns still to come before the two automatic qualifying spots and the play-off place are secured.
There had been plenty of guesswork about personnel in an intense build-up to the game and the Scotland team sheet showed that Strachan, back at his former club, made three changes with left-back Andy Robertson, stopper Grant Hanley and midfielder Charlie Mulgrew returning as Steven Whittaker moved to right-back.
Irish manager Martin O'Neill, another ex-Celtic boss, lost midfielders Glenn Whelan and James McCarthy to injury but the shock news was that skipper and top scorer Robbie Keane had been dropped to the bench.
Republic fans had been officially allocated around 3,200 tickets but there were a few thousand more Irish accents in the ground at kick-off, helping create quite a din, albeit it took quite a while for the stadium to fill up to almost its 60,000 capacity.
Amid a cracking atmosphere, the question of whether Republic of Ireland's Scots-born winger Aiden McGeady would get booed on his return to his old ground was answered in the affirmative by the Tartan Army, who never let up.
However, there was more for them to focus on in a frantic opening as Scotland keeper David Marshall was tested by Jon Walters before Scots striker Steven Fletcher headed a Maloney corner over the bar.
A tetchiness then enveloped the match.
In the 12th minute Hanley was booked by Serbian referee Milorad Mazic for a desperate tackle on Shane Long and then McGeady and Jeff Hendrick were shown yellows for fouls on Fletcher and Whittaker respectively.
In the 34th minute Mulgrew bulleted a header from a Maloney cross past the post from six yards as Scotland turned the screw and the home fans at last found their voice.
Four minutes from the break, Fletcher failed to get on the end of a Maloney cross after the former Celt delightfully pulled a Russell Martin pass out of the air, and another opportunity for Scotland was lost.
O'Neill's side came out for the second-half in a more purposeful mode and in the 50th minute, from a fine McGeady cross, Hanley did well to challenge Walters and concede a corner which came to nothing.
Moments later, from another Irish corner, Walters' flick was helped on by Long from close-range with the home fans palpably relieved to see Marshall make the save.
Fletcher was replaced by Chris Martin but Marshall again came to Scotland's rescue by pushing an angled-drive by McGeady past the far post for another James McClean corner, which he confidently plucked out of the air.
In the 65th minute, with the game tantalisingly balanced and not for those of a nervous disposition, Martin screwed a Steven Naismith pass inches past Forde's left-hand post from eight yards out.
Long and Darron Gibson were soon replaced by Robbie Brady and Stephen Quinn in a double substitution but to no avail.
Off a whipped-in free-kick from Mulgrew, Walters headed the ball against the top of his own crossbar but the luck of the Irish immediately went missing.
Maloney took a short corner to skipper Scott Brown, then took the clever return pass and curled the ball from 16 yards past Forde and into the far corner and Parkhead erupted.
O'Neill threw on Keane for Hendrick and the Scots were forced into some desperate defending but saw out four additional minutes - in which the ball came off their bar in a last-ditch Irish attack - to the cheers of the home fans who may already have the scent of France in their nostrils.