Glassgow: Rangers scored three second-half goals as they came from behind to defeat ten-men Celtic 4-2 at Ibrox to move four points clear at the top of the Scottish Premier League.
Steven Naismith opened the scoring at Ibrox in the 22nd minute with a superb shot before Gary Hooper fired Celtic level in the 34th minute.
Allan McGregor had gone into the game on the back of five consecutive clean sheets but the keeper was at fault when he allowed Moroccan Badr El Kaddouri`s soft effort from 25 yards to slip through his legs to hand the Hoops a half-time advantage.
Nikica Jelavic headed Rangers level seven minutes after the break before Lafferty, who had already had an effort chopped off for offside, fired Rangers ahead in the 67th minute.
Charlie Mulgrew saw red for his second bookable offence in the 75th minute before Naismith got his second in injury time as Rangers continued their unbeaten start to the campaign.
"I didn`t think there was an awful lot between the teams in the first-half. I`m not sure we deserved to go in 2-1 down but that`s what we were faced with," said Rangers manager Ally McCoist, who was delighted to win his first Old Firm match in charge.
"We asked the boys for a reaction in the second-half and boy did we get it."
Meanwhile, opposite number Neil Lennon was disappointed with his side`s second-half performance.
"We didn`t compete and it was almost as if the players had gone out in the second-half thinking the game was won," the Celtic boss said.
"When you play in these games you have to earn the right to play. We did that first-half but in the second-half we lost the physical battle."
Naismith gave Rangers the lead with his first Old Firm goal, lashing an unstoppable shot into the top left-hand corner with the outside of his right foot after latching on to a poor Kelvin Wilson clearance.
The Rangers defence had rarely looked under pressure before a cool finish from Hooper brought the visitors level on 34 minutes.
Scott Brown played Hooper in with a neat pass and the Englishman sent a low angled shot from ten yards into the bottom left-hand corner.
Rangers stopper McGregor had gone 558 minutes without conceding before Hooper`s goal but a blunder from the keeper handed Celtic a 41st-minute lead when he somehow allowed El Kaddoouri`s low drive from 25 yards to wriggle through his legs on the goal-line.
The home side almost found themselves level just 42 seconds after the restart when Steven Davis sent a volley from 20 yards crashing off the crossbar.
Lafferty then had the ball in the net after great link-up play involving Naismith and Jelavic but the Northern Irishman`s sidefooted effort was wrongly ruled out for offside.
But Rangers` determined start to the second-half paid off in the 54th minute when Jelavic equalised, heading a Davis corner down into the ground and up into the roof of the net.
The Ibrox side should have found themselves ahead two minutes later when Wylde picked out Lafferty in the box but the forward headed over from six yards, and Lafferty had an even better chance moments later when he latched onto El Kaddouri`s slack headed backpass only to poke his effort wide.
El Kaddouri immediately made way for Anthony Stokes before Glenn Loovens saw his header from Mulgrew`s corner smack off the base of the post. Lafferty finally got his goal in the 67th minute.
Jelavic`s header from Wylde`s cross was stopped but Lafferty reacted quickest and saw his initial shot blocked before making room to fire a low shot past Forster at the second attempt.
Mulgrew, who had been booked for a late challenge on Naismith in the first-half, was given his marching orders in the 75th minute for a second bookable offence when he scythed down Davis.
Naismith made sure of the points in injury time when he got on the end of Davis` cross to tap home from close range.