It's always a momentous occasion when Rangers and Celtic clash but the fallout from Sunday's match could go on for some time.
An improved performance from Neil Lennon's side saw them dominate until Nir Bitton's moment of madness saw the Israeli sent off.
A Callum McGregor own goal handed the hosts a 1-0 win and a surely insurmountable 19 point lead at the top of the table.
Celtic have three games in hand but even with victories in each and every one they'd be staring down the barrel of a double-digit gap.
As always tensions were running high and commitment was at its fullest. Here are four clashes that defined the match.
Steven Gerrard vs Neil Lennon
It wasn't just a tactical battle between the two managers as things got heated on the touchline.
Early on the Celtic boss appeared to take exception to something said by Rangers fitness coach Tom Culshaw.
Lennon turned to remonstrate with the man in the other dugout only for Gerrard to intervene.
On the pitch it was the visiting manager who had the upper hand as his midfield diamond and high full-backs overwhelmed Rangers.
Gerrard introduced Ianis Hagi at half-time, helping his side keep the ball more effectively in the final third before the red card changed the game.
Borna Barisic vs Jeremie Frimpong
Playing a midfield diamond against Rangers could have been risky, given the attacking output of Borna Barisic and James Tavernier.
Lennon started with Frimpong and Diego Laxalt, two very attacking players, with the aim of pinning the Rangers men back.
With his pace Frimpong looked dangerous down the right hand side, particularly in the first half, with Barisic struggling to get forward and impact the game.
However, the Dutchman's final ball often left a lot to be desired as he completed just 77.5 per cent of his passes.
Steven Davis vs Ismaila Soro
Midfield was always going to be a key battle and Celtic certainly had the better of it in the first half.
With no Ryan Jack the hosts struggled to deal with the intensity presented by the likes of Soro and David Turnbull.
Davis' pass success rate dropped from an average of 88.2 per cent this season to 83.6 per cent, with 61 passes compared to 83 against St Mirren in midweek.
The Northern Ireland international was also booked for a crude tackle on Kris Ajer.
After Bitton's red card though more space and time opened up for Davis and he began to exert his calming influence on the game.
Allan McGregor vs Leigh Griffiths and Odsonne Edouard
If and when Rangers go on to win the title McGregor's performance on Saturday will enter straight into folklore.
Celtic started the game at a furious pace and at times it seemed as though it was only the veteran goalkeeper holding the tide at bay.
McGregor got down sharply to save an early Odsonne Edouard shot and made an arguably even better save on the rebound. The Frenchman was offside on the follow-up but the keeper wasn't to know that.
He did even better when Leigh Griffiths' strike appeared to be bending into the top corner only for McGregor to get his fingertips to the ball and divert it onto the post.
