Match ends, Celtic 3, Dundee United 0.
Manager Neil Lennon praised "class act" David Turnbull as resurgent Celtic prepared for Saturday's Old Firm derby with a convincing Scottish Premiership win over Dundee United.
Turnbull - a £3m summer signing from Motherwell - scored for the third game running after Ismaila Soro's opener.
Odsonne Edouard's lob sealed a sixth straight win, but it came at a cost as Christopher Jullien went off injured.
"He's hit the ground running now," Lennon said of 21-year-old Turnbull.
"He had to wait a wee while to get to the pace of how we want him to play, but now he's in excellent form. There's no reason for me to leave him out."
With Soro netting his first Celtic goal, having kept captain Scott Brown out of the team for three games, Lennon says his selection decisions are a "nice choice to have" as his team head to Ibrox 16 points behind Rangers with three games in hand.
A minute's silence was observed before kick-off in memory of legendary United manager Jim McLean, who died on 26 December at the age of 83.
McLean was in charge of the Tannadice club the last time they won at Celtic - 28 years ago - and Micky Mellon boldly shoehorned strikers Lawrence Shankland, Marc McNulty and Nicky Clark into his starting line-up as he attempted to end that long barren run.
There was a big call from Lennon too, with Greek goalkeeper Vasilis Barkas restored in place of Conor Hazard after five games on the bench. The Celtic boss later confirmed Barkas will remain in goal against Rangers.
Soro delivered an unlikely opener midway through the first half with a swerving 25-yard drive into the top corner. A moment to savour for the Ivorian, but one to forget for goalkeeper Benjamin Siegrist, whose attempted save was feeble.
Still, United's margin of defeat could have been much heavier had Siegrist not partly redeemed himself with a number of stops.
He made an instinctive block after Turnbull's outrageous lob teed up Leigh Griffiths for a blast at goal, with Edouard sending the rebound wide.
But another long-range drive doubled the lead as Turnbull drilled home low off the keeper's right-hand post to score for his fourth goal in six games.
United, anonymous as an attacking force in the first half, almost conjured an instant response after the break as McNulty beat Jullien to Shankland's through ball and fired past Barkas. Jullien raced back to clear off the line, but his impetus took him thudding into the upright and, after several minutes' treatment, he was replaced with Nir Bitton.
United's positive spell - and Celtic's shakiness at the back - continued when Shankland's cross found Clark 10 yards out, but with only the goalkeeper to beat, the striker fired horribly wide.
That was as good as it got for the visitors as Celtic regained control. Griffiths and Edouard were both foiled by Siegrist before the strike pair combined to craft a sublime third.
Griffiths' lofted pass split United's defence and Edouard deftly lobbed the keeper as Celtic continued their resurgence before the crucial showdown with Rangers.
Man of the match - David Turnbull
What did we learn?
This was a crucial but costly win for a Celtic side still trying to claw back lost ground in the title race. A fourth consecutive Premiership victory and clean sheet are further evidence of their recovery, but the loss of Jullien would be a hammer blow for the trip to Ibrox.
Lennon will at least be consoled by his side's attacking verve, with Turnbull again impressive while the front two of Edouard and Griffiths worked in tandem to torment the visitors.
United's starting line-up was bold but failed to pay off as Mellon's team were far too passive in a first half that effectively killed the game as a contest. Standing off and allowing players to shoot cost them the first two goals and their strong start to the second half was let down by wayward finishing.
What did they say?
Celtic manager Neil Lennon: "We played brilliantly and created a lot of really good chances.
"There was great energy and quality. The atmosphere around the place is good and I was really pleased with the substitutes as well, their contribution was excellent."
Dundee United manager Micky Mellon: "We have to show growth and improvement from the lessons we learned today. The chances we made were more than reasonable and at Celtic Park you need to take them."
Derby dates for both sides. Celtic face Old Firm rivals Rangers at Ibrox on Saturday (12:30 GMT), while United are in New Firm action away to Aberdeen (15:00 GMT).
- 2JullienSubstituted forBittonat 51'minutes
- 12SoroSubstituted forBrownat 80'minutes
- 14TurnbullSubstituted forRogicat 77'minutes
- 9GriffithsSubstituted forAjetiat 77'minutes
- 22EdouardSubstituted forElyounoussiat 80'minutes
- 2SmithBooked at 56minsSubstituted forBoltonat 83'minutes
- 17RobsonSubstituted forSpörleat 83'minutes
- 8PawlettBooked at 38minsSubstituted forPowersat 74'minutes
- 24ShanklandSubstituted forMcMullanat 68'minutes
- William Collum
- Shots on Target
Second Half ends, Celtic 3, Dundee United 0.
Attempt blocked. Tomas Rogic (Celtic) right footed shot from the centre of the box is blocked. Assisted by Mohamed Elyounoussi.
Offside, Celtic. Diego Laxalt tries a through ball, but Jeremie Frimpong is caught offside.
Attempt blocked. Mohamed Elyounoussi (Celtic) right footed shot from outside the box is blocked. Assisted by Tomas Rogic.
Foul by Mohamed Elyounoussi (Celtic).
Dillon Powers (Dundee United) wins a free kick in the defensive half.
Attempt saved. Mohamed Elyounoussi (Celtic) right footed shot from outside the box is saved in the centre of the goal. Assisted by Callum McGregor.
Foul by Diego Laxalt (Celtic).
Luke Bolton (Dundee United) wins a free kick in the defensive half.
Substitution, Dundee United. Adrián Spörle replaces Jamie Robson.
Substitution, Dundee United. Luke Bolton replaces Liam Smith.
Attempt blocked. Diego Laxalt (Celtic) left footed shot from outside the box is blocked.
Corner, Celtic. Conceded by Jamie Robson.
Foul by Albian Ajeti (Celtic).
Mark Connolly (Dundee United) wins a free kick in the defensive half.
Attempt missed. Ryan Edwards (Dundee United) header from the centre of the box misses to the left following a corner.
Substitution, Celtic. Scott Brown replaces Ismaila Soro.
Substitution, Celtic. Mohamed Elyounoussi replaces Odsonne Edouard.
Corner, Dundee United. Conceded by Diego Laxalt.
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