A dramatic late Tom Rogic equaliser ensured Celtic took advantage of Rangers' defeat with a 2-2 draw at Livingston, taking them 13 points clear at the top of the Scottish Premiership.
Hoops midfielder Callum McGregor thundered in the opener from the edge of the box in the 16th minute before Livi captain Jon Guthrie levelled eight minutes later after a Fraser Forster fumble.
Midfielder Scott Robinson, who scored in the Lions' 2-0 win over the Hoops in October, notched less than a minute after the break. However, at the death, substitute Rogic slammed in an equaliser to take Celtic 13 points clear of Old Firm rivals Rangers, who lost 1-0 at home to Hamilton.
Rangers have a game in hand but Celtic showed just how determined they are to make it nine titles in a row this season after fighting back from behind against a spirited Livingston at a febrile Tony Macaroni Arena.
How Celtic rescued a point at Livingston fortress
All eyes were on West Lothian as Livi attempted to repeat their previous shock win over the champions, who had recorded their 34th consecutive domestic cup-tie victory on Sunday with a 1-0 William Hill Scottish Cup quarter-final win at St Johnstone.
Attacker Elyounoussi returned to the Hoops side to partner striker Odsonne Edouard at the expense of Leigh Griffiths, while Robinson replaced Jack McMillan and former Celtic defender Efe Ambrose made his home debut.
The visitors took the lead moments after Hoops keeper Forster had tipped a long-distance effort from Robinson past a post. When the Parkhead side raced up the other end, defender Steve Lawson failed to connect with his clearance from Greg Taylor's cut-back and the ball fell to McGregor, who switched the ball on to his right before driving high past goalkeeper Robby McCrorie, on loan from Rangers.
But Forster was at fault for Livingston's unexpected leveller - the Southampton loanee failed to gather centre-back Ciaron Brown's long throw-in under pressure from Guthrie and the Livi defender hooked the ball over his head and into the net. Despite some hopeful Celtic looks towards referee Willie Collum to blow for an infringement, the goal stood.
In the 35th minute Celtic defender Christopher Jullien headed a Ryan Christie free-kick over the bar. Edouard then crashed a shot off a post after being set up by McGregor, who had robbed Lawson on the touchline, before McCrorie punched away a shot from Taylor with the last action of the first half.
Celtic and their fans were stunned within a minute of the second half when striker Lyndon Dykes outmuscled Jullien on the right-hand side and rolled the ball back for Robinson to drive into the net from 14 yards.
Forster then saved Aaron Taylor-Sinclair's drive from wide with his feet moments later as Celtic wobbled before storming back.
Dykes missed the target with a curling shot after Steve Lawless played him in after picking up a loose Jullien clearance, but Celtic kept piling forward and only a timely tackle by Guthrie thwarted Edouard as he set himself to shoot just 12 yards from goal.
It was backs-to-the-wall defending by the home side, but in dramatic fashion Rogic converted an Edouard cut-back in stoppage time as Celtic were again rewarded for their never-say-die spirit.
What the managers said...
Celtic manager Neil Lennon: "I was delighted with the performance and we deserved three points. Against a difficult opponent on a difficult pitch, we were absolutely outstanding. I had total belief that we would get the equaliser. I am sitting here disappointed that it is the first two points we have dropped in 2020 and I didn't think we deserved it because we dominated the game for long periods and in the end we broke them."
Livingston boss Gary Holt: "I'm absolutely buzzing. They are an exceptional side. The never-say-die attitude from both teams to get something out of the game was in abundance. If they equalised in the third minute of the second half and it ends the same, you are still disappointed because you have had a lot of the game and had chances. But you play to the final whistle and we had chances to put the game beyond them. As an entertaining spectacle I thought it was excellent."
What's next?
Celtic host St Mirren on Saturday in the Scottish Premiership at 3pm, while Livingston travel to St Johnstone, also at 3pm on Saturday 7.