It was business as usual as Celtic secured a 14th consecutive Scottish Premiership win by subduing a hardworking Ross County in Glasgow.
County had given as good as they got before Erik Sviatchenko caught out goalkeeper Scott Fox with a 35-yard drive seven minutes before the break.
Stuart Armstrong drilled his second goal in two games in first-half stoppage time.
And Celtic convincingly extended their lead over Rangers to 16 points.
Brendan Rodgers’ side have now gone 23 domestic games unbeaten ahead of their visit to the home of their city rivals on Hogmanay.
County, who slip down to eighth, could feel hard done-by to find themselves two behind by half time, but the goals took the wind our their sails after a promising start.
Christie catches the eye
Any suggestions that Rodgers might want to wrap his key players in cotton wool ahead of the Old Firm game were quickly dispelled, with Ryan Christie the only unfamiliar starter.
In saying that, the midfielder’s performance may have given his manager food for thought. He was outstanding before being replaced after an hour by Liam Henderson.
It took Celtic a while to unlock a well-organised County defence.
The first clue that they might do so was when James Forrest went on a lengthy run across the park, evading tackle after tackle, before eventually poking the ball to Emilio Izaguirre, who whipped in a cross for Scott Sinclair to meet with a flashing header just past a post.
In fact, it took the champions 38 minutes to take the lead and the goal came from an unlikely source – and an unlikely method.
When Sviatchenko does score, it is usually a header from a set-piece, but this time he gathered the ball in the centre circle and advanced before releasing a shot that hardly left the surface as it beat goalkeeper Fox at his right-hand post.
One minute into time added on in the first half, it was 2-0.
Armstrong scored his eighth of the season and again it was a gem. The midfielder threatened to shoot with his left foot, checked on to his right and then back to his left again before rifling a low shot beyond Fox.
Celtic had chances to increase their lead, notably when a floated diagonal ball from Scott Brown was placed perfectly on the head of Leigh Griffiths, but the unchallenged striker put the ball over the bar.
The second half was a bit of an anti-climax, although the Parkhead faithful were screaming for a penalty when substitute Patrick Roberts was brought down by Marcus Fraser.
County were organised and pressed in high areas, trying to stop Celtic building from the back.
However, the champions had too much in reserve and go into the Glasgow derby in fine fettle and with a handsome lead over a Rangers side who dropped further behind after draw away to St Johnstone.
What the managers said
Celtic manager Brendan Rodgers: «We had to patient. We’ve seen that in recent games here when teams defend in a low block.
«The pitch is quite bobbly and it means the flow of the game is sometimes interrupted. But I think the players deal with that, technically, very well.
«Once we get the goal, then, of course, the opponent has to come out a bit more. Second half, we killed the momentum of Ross County and really controlled the opening 25 minutes and created more chances. Last 10 minutes, I thought we could have managed the game better. We gave away too many corners and got a little bit excited.»
Ross County boss Jim McIntyre: «We had a game plan to be hard to break down and still offer ourselves on the counter-attack. We certainly created two really good opportunities, with Liam Boyce and Alex Schalk. You need to take one of those chances when you come here.
«The first goal is really disappointing. Scott Fox knows he should be saving that. He’s been brilliant for us, so I can’t be too critical.
«It’s a shift for the players with Celtic’s movement and I thought they stuck to their guns well in the second half. We defended stoutly and had a couple of half-chances in the last 10 minutes.»