Maciej Zurawski's early goal gave Celtic a 1-0 win over Rangers at Ibrox and sent them 13 points clear in the SPL title race.
Polish international Zurawski was the hero for the Bhoys with the only goal of the game on 12 minutes.
And with Roy Keane at his most imposing, running the game from midfield, it led to a deserved three points for Gordon Strachan's team.
Celtic started strongly and were ahead when Zurawski fired low past Ronald Waterreus after being played in by Stilian Petrov following some shambolic Rangers defending.
Rangers desperately tried to get back into the game, but while their play was frenzied and disjointed Celtic in contrast knocked the ball around confidently.
Nacho Novo did have a chance for the home side when he met a Sotirios Kyrgiakos knockdown only for his own header to be held by Celtic keeper Artur Boruc.
And Rangers should have equalised just before half-time when Thomas Buffel skipped past his marker and only had the goalkeeper to beat.
But he chose to play the ball to Novo instead, overhit the pass and failed to find his team-mate in front of an empty net.
After the break Rangers continued to pile forward, and Steven Smith and Dado Prso both failed to find the target with decent chances.
Keane was booked for a challenge on Prso on the hour, but it was a momentary blight on an otherwise impressive Old Firm debut.
The closest Rangers came to an equaliser was a Kyrgiakos header from a free-kick that flashed narrowly wide.
But Alex McLeish's final Old Firm game in charge at Ibrox ended in defeat, and his team are now 21 points behind their bitter rivals in the SPL table.