Scorers: Celtic - Griffiths (47, 65, 84pen)
The striker maintained his blistering recent form with a second-half hat-trick which put Dundee United to the sword and leaves Celtic eight points clear of nearest rivals Aberdeen at the top of the table with four games of the campaign remaining.
Griffiths has now scored 14 goals in his last 17 appearances for Ronny Deila’s side, taking his overall tally for the season to 18.
His contribution yesterday sparked Celtic into life after a drab first half against a youthful United side whose own miserable run of form continues. Jackie McNamara’s side have won just one of their last 13 games and are now out of the European qualification places.
For United supporters, the familiarity of this fixture certainly helped breed a level of contempt towards their club’s hierarchy last month when four consecutive meetings of the teams in three different competitions brought nothing but disappointment for the Tannadice men.
Securing Europa League participation for next season would at least allow McNamara to salvage something tangible from a campaign which has turned sour since the transfer deadline-day sales of Stuart Armstrong and Gary Mackay-Steven to Celtic.
Armstrong, in Deila’s starting line-up with Mackay-Steven beginning the afternoon on the bench, was greeted with some mild jeering by a section of the home support during the early stages of his return to the ground where he made his still burgeoning reputation.
In a low-key start, lacking any of the intensity which so often boiled over during the consecutive four-match series last month, Armstrong created the first clear opening with a perfectly delivered corner from the left. It picked out the head of Virgil van Dijk who perhaps should have done better than loop his effort over the crossbar.
United’s response was reasonably bright and progressive with the four teenagers in McNamara’s starting line-up all showing up well. John Souttar looked assured in a holding midfield role, while the more advanced trio of Blair Spittal, Charlie Telfer and Robbie Muirhead were all involved in eye-catching moments which kept the Celtic defence on their toes.
Ryan McGowan should have put United in front in the 19th minute. Unmarked as Spittal whipped in a corner from the left, the big Australian defender wastefully glanced his header wide from close range.
Muirhead, making his first start since joining from Kilmarnock in the last transfer window, then tried to catch out Craig Gordon with a dipping snapshot from around 22 yards. The ball may have been going over but the Celtic ’keeper could take no chances as he arched backwards to help it on its way.
Much of Celtic’s work going forward lacked the kind of energy and inventiveness which Deila craves from his players. It took them until the 25th minute to force Radoslaw Cierzniak into a meaningful save, the Pole getting down to his left to touch wide a shot by Kris Commons which took a deflection off Souttar on the way.
Van Dijk then missed another more than decent opportunity, stabbing a shot straight at Cierzniak after a slick move involving Commons, Armstrong and Emilio Izaguirre down the left had carved out the opening.
The general lack of effective tempo in Celtic’s play, however, was clearly something Deila would seek to address during his half-time briefing to his players.
They provided him with the perfect response, making the breakthrough less than two minutes after the resumption with a briskly created and clinically executed goal.
Armstrong and Scott Brown helped stretch the United defence across the edge of the home penalty area with some sharp passing, before Stefan Johansen delivered the ball invitingly into the path of Griffiths on the right. The striker took it in his stride and arrowed a low, right-foot shot across Cierzniak and into the far corner of the net.
The goal provided Celtic with real impetus for the first time and they were quickly threatening to put the game firmly beyond United.
Cierzniak kept his team in contention with a string of fine saves. He reacted brilliantly to keep out a close-range diving header by Commons, then got down well to stop efforts from distance by both Commons and Johansen.
A second goal for the visitors appeared inevitable and it duly arrived, albeit in scrappy circumstances, in the 65th minute.
Mackay-Steven, who had just replaced Armstrong to a mixed reception from the United fans, floated over a corner from the left which Van Dijk contested with Callum Morris. The ball came off the United defender’s head, struck Cierzniak’s right-hand post and broke to Griffiths at the other side of the six-yard box. The striker’s initial effort was clawed out by Cierzniak, although it looked as if the ball had crossed the line. Griffiths spared any controversy by bundling home from close range.
Mackay-Steven’s introduction brought fresh zest to Celtic in the closing stages as they cruised to all three points. He was unfortunate to see a fierce shot smash back off the crossbar in the 81st minute, before he earned the contentious penalty which allowed Griffiths to complete his hat-trick.
John Rankin’s foul on Mackay-Steven clearly looked to have taken place outside the area but, after brief hesitation, referee Willie Collum pointed to the penalty spot.
Griffiths coolly sent Cierzniak the wrong way to wrap up a satisfying afternoon for the champions.