A thrilling Scottish Premiership title race reached new heights on Wednesday with arguably the most dramatic night of the season.
Leaders Hearts, chasing a first top-flight crown since 1960 and the first by a non-Old Firm team since 1985, beat Falkirk 3-0 at Tynecastle to stay at the summit.
The real drama came at Fir Park, where second-place Celtic came from behind to lead Motherwell 2-1, before conceding an 85th-minute equaliser to seemingly squander two precious points. However, they were awarded a controversial late penalty following a VAR check for handball, with Kelechi Iheanacho converting from the spot nine minutes into stoppage time to secure a vital victory.
The permutations facing Hearts and Celtic on Scottish Premiership's final day
If the game at Motherwell had ended 2-2, Hearts would have gone into the final day of the Scottish Premiership season three points ahead of their title rivals, with their goal difference healthier by six.
Instead, Celtic are just a point behind Derek McInnes' side - who they host in a winner-takes-all finale on Saturday lunchtime.
The maths is simple: if Celtic win, they will leapfrog Hearts and lift the title for the fifth successive season. Any other result would see McInnes' men crowned champions for the fifth time ever.
The two sides cannot finish level on points due to playing each other at Celtic Park, but when that situation arises, the Scottish Premiership has a clear set of criteria.
Goal difference acts as the first tie-breaker to decide which team finishes highest, with Hearts on +35 and Celtic on +30. If they are level on goal difference, it is decided by goals scored, where Martin O'Neill's men have the edge - finding the net 70 times this term compared to their rivals' total of 66.
If they still cannot be separated, it would then come down to head-to-head record. Ahead of their fourth and final meeting of the season on Saturday, Hearts have beaten Celtic home and away this term, with the sides also drawing 2-2 at Tynecastle in January.
Hearts clearly have the edge on head-to-head record, but if the teams were level on that metric, it would be decided by head-to-head goal difference, which the Edinburgh side lead 7-4.
Hearts set the pace in Scotland thanks to a 12-game unbeaten run at the start of the season, while Celtic toiled in the first half of a campaign in which they have had three permanent managers.
Frenchman Wilfried Nancy was sacked in January, just one month after taking the job, and the Glasgow giants were six points behind Hearts when legendary boss O'Neill returned for his second spell of the campaign.
Celtic have lost just twice in the league under the Irishman to narrow the gap on a Hearts side who have coped admirably with the pressure, coming from behind to beat Hibernian and Rangers in recent weeks.
