Chris Sutton hit his second hat-trick in four games as Celtic recorded their 12th straight league victory with a crushing 5-1 win at Dundee United on Saturday.
Swedish striker Henrik Larsson claimed the other two goals to help Celtic move eight points clear at the top of the Scottish premier league before Rangers' match at home to Aberdeen later on Saturday.
Celtic had 37 points from 13 games while champions Rangers were on 29 from 12 and Martin O'Neill's side can now look forward with confidence to Tuesday's Champions League encounter with Bayern Munich.
"The players are playing very well at the moment," said O'Neill. "The second-half was great for us and we played very well indeed after weathering plenty of uncomfortable moments in the first-half."
Celtic were indeed fortunate to be ahead at halftime as Sutton benefited from home defender Chris Innes' mistake to score on 32 minutes, but they ripped the heart out of a mediocre United with a three-goal flurry in six minutes after halftime.
Celtic defender Stanislav Varga could have been sent off towards the end of the first-half for a body check on Barry Robson when he had already been booked, but that was the only moment of real concern for the visitors.
Larsson nodded home the second goal on 52 minutes from Stilian Petrov's corner before Sutton tapped in the third four minutes later after goalkeeper Paul Gallacher had failed to get hold of Larsson's lob.
The Swede then rifled home a blistering effort on 58 minutes with United's defence in a shambolic state.
A mistake by Didier Agathe allowed United's Jim McIntyre to score with 14 minutes remaining, but Celtic were not finished and Sutton tucked away an 81st penalty after he had been felled by a clumsy Alan Archibald tackle.
Sutton also scored three goals in the 5-0 drubbing of Kilmarnock on November 1.