Julian Araujo kept Celtic's title chances alive as his 97th-minute winner sealed a stunning comeback from 2-0 down to a 3-2 victory at Kilmarnock.
With the top two in Hearts and Rangers facing off at Ibrox later on Sunday, Martin O'Neill's side knew they had to win to put the pressure on - but got off to the worst possible start.
After his hat-trick against St Mirren in midweek, Tyreece John-Jules curled Killie in front after poor defending from Celtic defender Auston Trusty, before Joe Hugill headed in a second, amid questionable goalkeepeing from Kasper Schmeichel.
O'Neill responded with a half-time triple substitution - including the introduction of Alex Oxlade-Chamberlain - but it was another replacement who brought Celtic back in it as Sebastian Tounetki curled in a sensational goal back from 25 yards.
And eight minutes later, Celtic had their leveller as Araujo's long throw went all the way through to Benjamin Nygren, who finished from close range to net his 16th goal of the season.
Despite the Celtic comeback, it was Kilmarnock who had the better chances to win it. John-Jules - who came off with a thigh injury - hit the crossbar with a stunning free-kick, while Robbie Deas nodded over from close-range after a corner was flicked into his path.
At the other end, Tounetki put a decent headed chance wide, before Callum McGregor's shot from distance tricked past the post.
But the winner then came on 97 minutes as Araujo slammed home from inside the box as Kilmarnock failed to clear a corner.
The result, coupled with Hearts' defeat to Rangers at Ibrox - means Celtic are now three points off the top of the Scottish Premiership, with a game in hand.
Celtic head coach Martin O'Neill to Your Site:
"There's some spirit in the team, there's no doubt about that. It's not just a fluke. We were 2-0 down at half-time, out of the game and have not played well at all. The second half was just fantastic.
"The message at half-time was simple: get into the game, properly. We created a few chances in the first half, missed a chance or two, but overall our play was very sloppy. I don't think we adapted to the conditions and the way Kilmarnock were playing.
"Kilmarnock were very strong, so we had to make changes at half-time. The players came on and made a big impact.
"It's happening too often. I don't think you can keep that going. But they do play to the end, that's the lovely thing about them. The spirit and determination within them: well done then.
"Who knows? It's a game that we've won now, after being well and truly out of it at one stage. We feel this group are never really out of it. To fight back in the manner we did was very pleasing. Who knows at the end of it?"
Your Site' Adam Binnie:
For the third consecutive game in just eight days, Martin O'Neill's Celtic were rescued in injury-time.
It's been a feature of many great title-winning Celtic sides for years. Even in recent history, think back to Matt O'Riley v Motherwell (2023), Girogos Giakoumakis v St Johnstone (2022), or even Anthony Ralston v Ross County (2021).
All goals where at the time we said would prove crucial in the title race. Goals that make champions.
But this year is different, and these late winners actually will make a difference. The league is no canter this year - it's quite the opposite, and Celtic have the crucial ingredient of winning experience.
They have a core of serial winners, who know nothing but success: Kieran Tierney, Callum McGregor, James Forrest to name a few.
But a 'winning mentality' will only take you so far. The performance levels in the first half were once again extremely alarming.
O'Neill admitted: "I don't think you can keep that going." You're right, Martin. Some seriously tough games coming up, and you can't be bailed out in of them all in stoppage-time.
Kilmarnock head coach Neil McCann to Your Site:
"That's a sore one. A real sore one. I don't think we deserved to lose that game.
"Celtic - to their credit - went to the end. They always do. We said beforehand that it might be the case today. We didn't do enough to see the game out.
"You might have heard through these walls, but it's so disappointing. Seven minutes - I'm not sure where that came from. But whatever happens, we must deal with that. We have to manage things so much better. To come away with nothing after 97 minutes is so disappointing."
