Rangers have been crowned Scottish Premiership champions for the first time since 2011 after Celtic were held to a goalless draw at Dundee United.
Steven Gerrard has claimed the first major league title of his managerial career, with Rangers now holding an unassailable 20-point lead in the league table.
Rangers were consigned to Scotland's fourth tier back in 2012 after financial collapse, but have rebuilt steadily - and have now denied Celtic a record-breaking 10th consecutive top-flight crown.
Rangers fans flouted lockdown rules to celebrate at Ibrox for the second day running.
"After a superb campaign so far, Gers' win over St Mirren yesterday put them on the verge of glory, with results elsewhere today meaning they can mathematically no longer be caught, with incredibly six matches still to play," read a Rangers statement.
"It's title number 55 for the club - the most of any football club in the world - and the first in 10 years following one of the most arduous decades in the club's history."
Celtic's big team news on the day they lost their title was that winger James Forrest returned to the bench following ankle surgery for the first time since playing a Europa League against Riga last September and he would get on late in the game to bring some positivity to the Hoops camp.
Interim boss John Kennedy made one change from the side which beat Aberdeen in his first game as caretaker manager, with on-loan Southampton attacker Mohamed Elyounoussi in for striker Patryk Klimala.
Dundee United boss Micky Mellon brought back Nicky Clark and teamed him up with fellow attackers Lawrence Shankland and Marc McNulty but the home side offered little early threat.
As a plane circled Tannadice trailing a banner which read 'Can you see us now? #55 titles' in reference to Rangers' imminent 55th title win, Celtic, slick and speedy, kept up their early pressure.
Skipper Scott Brown headed a David Turnbull corner over the bar from six yards before Siegrist blocked an effort from Hoops left-back Diego Laxalt.
The Tayside outfit threatened only sporadically.
Celtic keeper Scott Bain clutched a lobbed shot from Ian Harkes and easily saved another long distance effort from the midfielder but in between Siegrist was again called into action to tip a drive from Celtic striker Odsonne Edouard over the bar.
Further efforts from Edouard and Callum McGregor followed before McNulty latched on to a Shankland pass but missed the target with only Bain to beat.
In the 34th minute Laxalt did the same, set up by Elyounoussi but slashing his drive wide and then Siegrist pushed a Turnbull drive wide.
Celtic also began the second half on the front foot and from another Turnbull corner, Siegrist blocked with his knees Stephen Welsh's powerful close range header and the home side survived yet again.
The United keeper made saves from Ryan Christie and Elyounoussi before the game was held up momentarily around the 55th minute after flares were thrown on to the edge of the pitch from outside the stadium.
In a rare United attack with Celtic stretched at the back, McNulty's 20-yard shot was pushed behind by Bain but normal service soon resumed with Elyounoussi missing a great chance with his head from a Christie cross before screwing a drive wide of the far post.
Forrest replaced Brown and Leigh Griffiths came on for Elyounoussi but in the end Celtic were ragged and desperate, as they failed to stop their crown slipping off.
