Aberdeen 0 Celtic 2
Celtic moved back nine points clear of Rangers at the top of the Ladbrokes Premiership with a 10th successive win over Aberdeen.
Striker Moussa Dembele put the visitors ahead with a header in the 37th minute at Pittodrie.
Despite Hoops right-back Mikael Lustig being sent off by referee Bobby Madden for a second booking in the 76th minute, the champions doubled their lead through left-back Kieran Tierney in the 83rd minute.
A minute later Dons substitute Sam Cosgrove, on for Stevie May in the 76th minute to make his debut after signing from Carlisle on transfer deadline day, was shown a straight red card for a foul on Parkhead skipper Scott Brown.
Celtic were knocked out of the Europa League by Zenit St Petersburg on Thursday night but with the 2-0 win they once again showed their domestic quality and tenacity which will surely see them take the title again.
The visitors, who had Scott Sinclair and Tom Rogic back in the starting line-up, started with assurance against a tentative-looking Aberdeen side but could have found themselves behind in the seventh minute, after Hoops stopper Jozo Simunovic had fouled the returning May.
Midfielder Kenny McLean, captain in the absence of the suspended Graeme Shinnie, whipped in a terrific in-swinging free-kick from the right which defender Kari Arnason, himself in for loan attacker Ryan Christie, missed only by inches.
However, Celtic began to turn the screw.
Sinclair struck the crossbar with a swirling corner from the left in the 16th minute then Dons keeper Freddie Woodman made a save at point-blank range from Rogic, before Brown fired over the crossbar.
As the game opened up further, McLean's wonderful pass on the half-turn just evaded May as he raced in on Hoops goalkeeper Dorus de Vries.
Woodman was called into action again just after the half-hour mark when Rogic raced through alone but his header was parried by the Aberdeen keeper at the edge of the box.
Moments later, a powerful 25-yard drive from Olivier Ntcham rebounded off the post and the Dons escaped again.
However, the opening goal eventually came when winger James Forrest took a pass from Rogic, went easily past left-back Andrew Considine and stood up a cross for 21-year-old Dembele to escape the attention of Arnason and head in from under the bar, for his 10th of the season.
There was a scare for the Hoops on the hour mark when Simunovic clashed heads with his own team-mate Kristoffer Ajer, leaving the Norwegian prostrate and the ball found its way to former Celtic man Gary Mackay-Steven but his cross could not find May.
After a lengthy spell of treatment Ajer carried on with a bandage on his head while Aberdeen went in search of an equaliser.
In the 73rd minute De Vries parried an angled drive from McLean, Niall McGinn's follow-up shot was blocked by Ajer before Lustig headed Anthony O'Connor's third attempt away.
The Swedish defender, booked in the first half for a foul on Mackay-Steven, was shown a second yellow for a foul on the same player which gave the home side added impetus.
But in a classic breakaway Dembele raced forward and played in Tierney who rifled past Woodman, with Cosgrove showing his frustration with his reckless tackle on Brown.