Rangers came from behind to beat Celtic 3-1 at Parkhead on Sunday to go three points clear at the top of the table, setting a new SPL record with a ninth straight win from the start of the season.
Steven Whittaker hit the post early on but it was the hosts who took the lead at the end of the first half - Gary Hooper scored at the back post when Ki's corner was flicked into his path.
Celtic had won their previous 16 Clydesdale Bank Premier League games under Neil Lennon but Rangers were level three minutes after the break when Kyle Lafferty latched on to a Steven Davis free-kick and the ball went into the net off defender Glenn Loovens.
SPL top scorer Kenny Miller gave Rangers the lead in 55 minutes when he slammed a low shot past keeper Fraser Forster from the edge of the box. He made sure of victory for Walter Smith's team with his 13th league goal of 2010/11 from the spot midway through the second half after defender Daniel Majstorovic had been penalised for a challenge on Kirk Broadfoot.
Rangers boss Walter Smith said of his 50th Old Firm match: "It's a great win for us and a great start to the season. I was a little bit disappointed to lose a goal just on the stroke of half-time but after that we had our best spell of the game by far. To have a Champions League game on Wednesday night and then to come out and play in this atmosphere on a Sunday, it's not easy."
Celtic manager Neil Lennon said: "We shot ourselves in the foot and I hope the players learn from today. I wouldn't mind if Rangers had cut us open but the manner of their goals was disappointing."