Glasgow - Celtic maintained their two-point advantage over Rangers at the top of the Scottish Premiership as both sides resumed after the winter break with victories on Wednesday.
The leaders bounced back from defeat to Rangers in the final game of 2019 with a 3-1 victory at Kilmarnock.
Odsonne Edouard fired the visitors into the lead in the 25th minute before Leigh Griffiths added a second at the start of the second half.
Celtic looked to be comfortably heading towards victory before Kilmarnock striker Nicke Kabamba pulled one back with a 66th-minute header.
But Christopher Jullien nodded home from a corner seven minutes later to secure the victory for the Hoops.
"It was a great performance at a difficult venue," said Celtic manager Neil Lennon, who reserved special praise for Griffiths.
The Scotland striker missed a large part of last season due to mental health problems and has been a peripheral figure since Lennon returned to the club in February.
"Griffiths has had a long time out of the game but I know what he can do. He's such a clever player."
Rangers still have a game in hand to come over their Glasgow rivals and overcame stubborn resistence from St Mirren to win 1-0 at Ibrox thanks to Jermain Defoe's 16th goal of the season.
Steven Gerrard's men were without the suspended Alfredo Morelos, but the evergreen Defoe proved the match winner in the Colombian's absence with a predatory finish 11 minutes before half-time.
"I understand that the supporters, even some of the players, expect us to win more comfortably, but I am delighted with the win and the clean sheet," said Gerrard.
Liam Donnelly scored the only goal of the game as third-placed Motherwell extended the gap between themselves and Aberdeen, who are fourth, to four points.
Paul Hanlon struck a late winner as Hibernian came back from a goal behind to defeat Hamilton 2-1.
Scott Pittman netted the only goal to give Livingston a 1-0 win over St Johnstone, while Ross County and bottom-placed Hearts played out a goalless draw.