Kai Andrews scored a late winner as Hibernian delivered another blow to 10-man Celtic’s William Hill Premiership title hopes.
The Hibernian substitute guided a composed finish into the bottom corner from the edge of the box in the 87th minute in what was a rare second-half attack for the visitors.
The 2-1 defeat left third-placed Celtic six points adrift of leaders Hearts and only four ahead of Motherwell.
Celtic fans had sensed an important day in the title race, with Rangers trailing by two goals at Livingston as their team launched wave after wave of attacks after Benjamin Nygren cancelled out Felix Passlack’s opener on the stroke of half-time.
But Auston Trusty received a VAR-assisted red card in the 74th minute following an off-the-ball incident and on-loan Coventry midfielder Andrews produced another twist in the dramatic Premiership title race.
Worse was to follow for the home fans as Rangers equalised in West Lothian to move two points above Celtic before the rivals meet at Ibrox next Sunday.
Celtic will have to do without Trusty in the derby after his second red card in seven games, unless they successfully appeal the dismissal.
Hoops manager Martin O’Neill stuck with Kasper Schmeichel – despite his poor performance in the midweek defeat by Stuttgart – and the goalkeeper made another blunder early on when he gifted possession.
Only a slack touch from Martin Boyle prevented the Denmark international having to deal with the consequences of his error himself.
Nygren came close from 20 yards but there were other chances for Hibs before the opener. Nicky Cadden and Boyle had efforts blocked and Owen Elding shot weakly at Schmeichel from a good opportunity.
The breakthrough came in the 24th minute from a wonderful first-time cross from Cadden to the back post, where Passlack dived to head home.
Cadden soon set up another excellent opportunity with a ball over the top that sent Boyle in on goal, but he was foiled twice by Schmeichel.
Celtic began to pile on the pressure but were at times guilty of overplaying in and around the box. Alex Oxlade-Chamberlain shot over and Yang Hyun-jun beat Raphael Salinger to a cross but saw his header bounce over the crossbar.
Tomas Cvancara was hampered by some tight marking from Rocky Bushiri from several chances and made a mess of his finish when the centre-back failed to intercept Yang’s cutback.
The equaliser came just as the fourth official put up the board for first-half stoppage-time. Nygren ran away from marker Dan Barlaser and stooped to nod home Kieran Tierney’s cross from six yards.
Celtic came out after the interval determined to get in front. Nygren threatened from long range and Yang saw an effort deflected wide from closer in.
The home fans raised the decibel levels after word of Livingston going two up on Rangers reached Celtic Park.
But the hosts suffered a major blow when Trusty was sent off after a VAR review showed the defender had aggressively pulled Jamie McGrath’s arm as the pair lined up for a corner.
Referee Matthew MacDermid decided the centre-back was guilty of violent conduct.
Celtic were still on the front foot and substitute James Forrest came close but a sucker punch came when Ante Suto laid the ball back for former Motherwell midfielder Andrews to finish.
It was the first goal of the 19-year-old’s career and it sealed Hibs’ first win at Celtic Park for 16 years.
