Dougie Imrie's dramatic injury-time penalty gave Morton a shock 1-0 Scottish League Cup third-round win over Celtic at Parkhead.
Five minutes into the extra period after a stalemate during normal time, the Ton midfielder scored from the spot after referee Bobby Madden adjudged Celtic defender Efe Ambrose to have handled when challenging substitute Archie Campbell.
Celtic, who had been lacklustre for most of the game, pounded the Morton box in an attempt to get back level and Charlie Mulgrew hit the post in the dying seconds.
However, on night of unlikely drama, the resolute visitors were not to be denied.
With the top tier of the stadium closed and the rest of the ground far from full, the first half was pretty uneventful not to say uninspiring.
Mulgrew, playing at left-back in a reshuffled Hoops side, came closest to scoring with a free-kick which was tipped away for a corner by Ton's French goalkeeper, Nicolas Caraux.
However, Morton, second-bottom of the Scottish Championship, defended stoutly for the rest of the 90 minutes without offering much of a threat in attack but Imrie's penalty was all they needed.
Hoops manager Neil Lennon had noted beforehand that he had not yet won this trophy as a manager and he will have to wait at least another year.
Little was expected of Allan Moore's men who arrived with only a smattering of players with top-flight experience, including Jonathan Page, Marc Fitzpatrick and Imrie.
Israel midfielder Nir Biton made his first start for Celtic while there was the rare sight of goalkeeper Lukasz Zaluska and midfielders Dylan McGeouch and Tom Rogic, as Mikael Lustig returned to right-back after recovering from a groin strain.
Despite the changes, it was still a strong Celtic side and in the early stages they had to contend with Greenock enthusiasm on and off the pitch.
However, in the eighth minute Biton somehow missed the target with a free header from a Mulgrew corner four minutes later, and as the home side stepped up the pace striker Teemu Pukki's low drive from 12 yards, after turning on a Derk Boeriggter cross from the left, was comfortably saved by Caraux.
There was little more of note until the 28th minute when Mulgrew's whipped-in free-kick was heading for the top corner until it was tipped over for a corner by the stretching Caraux.
The visitors were then under pressure for a few minutes until Biton brought some respite by driving over the bar from the edge of the box.
Six minutes from the break Morton wide man David O'Brien was carried off the field on a stretcher after appearing to hurt his shoulder in a challenge by the back-tracking McGeouch, and was replaced by Tony Wallace.
In the 55th minute Rogic drew a good save from Caraux with a 25-yard drive and on the hour mark Biton tried his luck with a shot from even further out and this time the Cappielow goalkeeper was down at his left-hand post to smother.
Anthony Stokes replaced Rogic and Adam Matthews came on for McGeouch, while Morton replaced their tiring lone striker Kabba-Modou Cham with Campbell.
With Lennon's last throw of the dice he brought on Kris Commons for Boerrigter but still the game slipped into extra time.
Imrie's penalty shook the home side who threw everything forward in their quest for a leveller.
Caraux saved from a Virgil van Dijk header with the Dutchman, who had moved into attack, coming closer moments later with a shot which bounced past the far post.
The second half of extra time saw the Hoops continue to bombard the Morton goal with Caraux making a fine save from Lustig from yet another Hoops corner with the Swede missing from close range.
Page cleared van Dijk's goal-bound header off the line and Mulgrew hit the post before the visitors heard the sweet sound of the final whistle.