Dedryck Boyata headed his second goal in three games to earn Celtic a 1-0 victory over Aberdeen and send the Ladbrokes Premiership leaders 25 points clear of closest title rivals Rangers.
The Belgian defender has seized his chance after stepping for the suspended Erik Sviatchenko against Albion Rovers and he netted his second winner in only his fifth appearance of the season.
Without a recognised striker, Celtic had toiled to break the Dons down before Boyata converted Scott Sinclair's 57th-minute free-kick, but Aberdeen had offered little sign that they could stop their hosts stretching their record unbeaten start to a domestic season to 28 games.
Brendan Rodgers had emerged from the transfer window with his team intact but he was without midfielders Stuart Armstrong and Tom Rogic plus strikers Moussa Dembele and Leigh Griffiths through injury.
The Celtic manager experimented with his formation in their absence.
Mikael Lustig, Jozo Simunovic and Boyata formed a back three with James Forrest and Kieran Tierney deployed as attacking wing-backs, while Sinclair and Callum McGregor supported Patrick Roberts up front. With Scott Brown and Nir Bitton sitting in midfield, Celtic at times looked like they had an old-fashioned five-man forward line as they hemmed Aberdeen in for long spells.
But for all their possession, they struggled to get in behind the visitors. Neither side managed a shot on target in the first half and each only came close once when Tierney and then Graeme Shinnie cut inside from the left and fired just off target with right-footed efforts.
The best first-half opening came in the 39th minute when a one-two between McGregor and Roberts sent the latter away but Ryan Jack's sliding interception stopped the on-loan Manchester City's square ball reaching Sinclair.
The second half started in the same fashion with Aberdeen containing their hosts but the breakthrough came after Tierney won a free-kick from Jonny Hayes on the left flank. Sinclair curled the ball in and Boyata escaped Ash Taylor with a near-post run before heading into the roof of the net from six yards.
The goal gave Celtic the space in behind they had previously been denied and Sinclair curled a shot on to the bar after a long ball put the Dons on the back foot.
The visitors' attempts to stop Celtic breaking grew increasingly desperate and Shinnie and Taylor were booked for cynical fouls before Mark Reynolds survived a penalty appeal when McGregor went down just inside the box.
When Celtic did manage to break beyond the visitors, Sinclair and Roberts both shot wide.
Aberdeen offered a vague threat as the game went into the final 15 minutes and Andrew Considine got a header on target, but Craig Gordon saved comfortably and Celtic further extended their Premiership leader courtesy of Rangers' heavy defeat by Hearts.