Celtic leapfrogged Rangers at the top of the Scottish Premier League with a 1-0 Old Firm derby victory which moves them two points clear of their rivals.
Joe Ledley's 52nd minute header from Charlie Mulgrew's corner was enough for the Hoops to claim a narrow victory over their Glasgow rivals in a match where they enjoyed the lion's share of chances.
However, Rangers will feel aggrieved at not claiming a point from the match after Lee Wallace's seventh minute header appeared to cross the line before keeper Fraser Forster scrambled the ball away.
The win was Celtic's ninth in a row and means they will top the SPL heading into 2012 after trailing Rangers by as many as 15 points at one stage in November.
Neil Lennon was delighted with the win.
"I think the first goal in these games is always important and I thought we were in the ascendancy at the time," the Celtic manager said.
"It was another good performance and that's real consistent form we're showing now. I can't ask any more of the players at the moment as they've been brilliant."
His Rangers counterpart felt a lapse in concentration in defence cost his side dearly.
"I didn't think there was an awful lot in the game to be honest," Ally McCoist said.
"But in a game like that you cannot afford to drop any level of concentration and I think we did that and that's what cost us the game."
At Celtic Park, the home side made two changes with Ki Sung-Yeung and Cha Du-Ri making way for Thomas Rogne and Adam Matthews while Rangers brought in Sone Aluko, Kyle Bartley and Kirk Broadfoot.
Celtic were the form team going into the match and started on the front foot with Carlos Bocanegra having to be alert to head away the danger from Gary Hooper's early effort.
Rangers thought they had taken a seventh minute lead when Wallace's header from Sone Aluko's cross looked to have crossed the line before Fraser Forster clawed the ball away but referee Willie Collum ignored their pleas.
At the other end Georgios Samaras chested James Forrest's cross into the path of Scott Brown but the Hoops captain saw his weak shot stopped by Allan McGregor.
Almost immediately Celtic had the ball in the net when the keeper spilled Hooper's fierce strike from 25 yards and Samaras dinked the rebound past McGregor but the Greek striker had already been flagged offside.
Bocanegra squandered a great chance in the 20th minute when Jelavic headed a corner towards goal which the American defender somehow turned over the bar from a few yards out.
Hooper caused a panic in the Rangers defence when McGregor couldn't hold his shot from range before Forrest fired his effort just over from a tight angle.
Samaras danced away from Kirk Broadfoot at the start of the second half only to see his effort cleared away by Bocanegra before McGregor made a fingertip save to turn Forrest's dipping shot over the bar.
However, Celtic were not to be denied and Ledley made the breakthrough in the 52nd minute when he met Mulgrew's corner at the back post in front of Broadfoot to head past the helpless McGregor.
Brown then fired over before McGregor got down low to save a Mulgrew free-kick as Celtic looked for a second goal to kill the match.
Rangers were lacking in attack and Jelavic squandered a rare chance when he volleyed over the bar from Kyle Lafferty's headed knock down.
The Hoops were dealt a blow in the 77th minute when Beram Kayal was stretchered off to be replaced by Ki after a collision with Lee McCulloch.
The Rangers midfielder was soon replaced by Maurice Edu while Wallace made way for David Healy as the Ibrox side looked but failed to find a way back into the game.
Elsewhere, St Johnstone defeated Kilmarnock 2-0, St Mirren and Dundee United drew 2-2, Aberdeen and Hearts ended goalless while Pat Fenlon picked up his first point as Hibs boss in a 1-1 with Inverness.