Rangers closed the gap on Ladbrokes Premiership leaders Celtic to two points – with a game in hand – after sealing a long-awaited victory at Parkhead.
Goals from Ryan Kent and Niko Katic earned Steven Gerrard's men a 2-1 victory and ensured there is a real title race ahead following the winter break.
Elsewhere, there were big wins for Livingston and Hamilton.
Here, the PA news agency looks at five things we learned from Sunday's Premiership action.
Rangers fuelled by power of belief
👊 Current Mood pic.twitter.com/TXjqE3rN8N
— Rangers Football Club (@RangersFC) December 29, 2019
Gerrard's team suffered heartache with their Betfred Cup final defeat, but their Hampden display proved to the Gers players they could go toe-to-toe with their bitter rivals and they took that confidence to inflict Celtic's first home derby defeat since 2010. The Ibrox boss will now hope that belief can carry them all the way come May.
Tired Celtic need a break
The Hoops have racked up 38 games already this season and that exhausting schedule showed as they ran out of gas against Gerrard's fired-up Gers. While the likes of Kent and Glen Kamara were running themselves into the ground, Ryan Christie and James Forrest looked stuck in second gear. The winter break could not come at a better time for the Hoops as they look to recharge the batteries for the second half of the campaign.
VAR clamour is unlikely to go away
Rangers came out on top but the Light Blues came away for the second derby running feeling like they got a raw deal from the officials. Gers were left complaining as Callum McGregor's strike cannoned off Odsonne Edouard's elbow before flying into Allan McGregor's net. It did not prove crucial but, with so much at stake, the cry for the introduction of replay technology is unlikely to go away.
Hearts will need to keep improving
🏆 Ladbrokes Premiership table going into the winter break pic.twitter.com/2CYcu7Yepo
— SPFL (@spfl) December 29, 2019
Daniel Stendel got his first point as Hearts manager five games into his Tynecastle reign with a 1-1 draw against Aberdeen, but the Jambos fell five points adrift at the foot of the table after Hamilton came from behind to beat Motherwell. St Mirren, St Johnstone and Ross County above them also picked up points to underline the need for Hearts to start putting a run together.
Kilmarnock need stability
Alex Dyer gave his reaction to Killie TV after our final match of 2019. pic.twitter.com/JxYDxwQVll
— Kilmarnock FC (@KilmarnockFC) December 29, 2019
Alex Dyer urged the Rugby Park board to make a permanent appointment during the winter break after he suffered a third defeat as caretaker boss. The 1-0 loss to St Mirren was Killie's fifth consecutive loss overall and they dropped out of the top six. Dyer said: "Whether I get the job or it's someone else, by the time we come back after the break it needs to be sorted. We have lost our identity a bit over the last few weeks. The stuff we were good at just isn't there at the moment."
