St Johnstone 2 - 5 Celtic: Substitute Dembele nets hat-trick
With the Scottish champions trailing 2-1 after an hour and their season-long unbeaten domestic run under threat, Thomson erred horribly to award them a penalty kick for handball against St Johnstone defender Keith Watson.
Dembele, who had just come onto the field as a substitute, converted from the spot with his first touch of the ball which he would go on to take home with him after two more goals to take his tally for the season to 23.
Celtic merited their 19th consecutive league win on the balance of play but the penalty was certainly a massive turning point in a hugely entertaining contest which saw them stretch their lead at the top of the Premiership to 27 points.
Liam Henderson’s sixth minute strike put Celtic ahead before a Watson header and an own goal from Dedryck Boyata earned Saints a half-time lead. The second half belonged to Dembele, complemented by a fine Scott Sinclair goal, but Tommy Wright and his team will simmer with resentment over Thomson’s part in their downfall for some time to come.
Since breaking into the Celtic first team as a 17-year-old under Neil Lennon’s management three years ago, midfielder Henderson’s development has unquestionably been advanced by his loan spells at Rosenborg and Hibs.
He has had to exercise patience at the champions this season but wasted little time in making the most of only his fourth starting appearance since Brendan Rodgers took charge.
The early warning signs were clear for a St Johnstone backline which had to adapt to the absence of their redoubtable captain Steven Anderson who missed out because of tonsillitis. Wright deployed a three-man central defence to try and compensate for the loss of his influential leader but there were immediately some uncomfortable moments for them as Celtic swarmed eagerly forward in the opening stages.
Zander Clark made a sharp save to deny Gary Mackay-Steven’s shot, after a slick move involving Patrick Roberts and Henderson, but the Saints’ goalkeeper found himself beaten from the subsequent corner kick.
The ball found its way to Roberts and when Clark could only parry his shot back out towards the edge of the penalty area, Henderson pounced to sweep a precise left foot shot high into the net from around 15 yards.
Celtic appeared primed to take complete control at this stage and Henderson was denied a second goal in the 10th minute when, after latching onto Kieran Tierney’s cutback, his shot was blocked by Tam Scobbie.
The home side, however, gradually secured a foothold in the contest, mainly due to the clever promptings of Swanson. He registered Saints’ first significant attempt on goal, seizing upon a slack clearance from Craig Gordon to drive a shot narrowly wide from 25 yards.
Swanson then led a sweeping counter-attack and picked out Richard Foster’s run into the Celtic penalty area with a superb through ball. Foster might hand done better with his finish, although Gordon’s advance from his line and blocking save was exemplary.
The game had developed a more evenly matched feel but Mackay-Steven should have given Celtic the comfort of a two goal lead in the 22nd minute, tamely shooting straight at Clark after being set up by Sinclair after a tremendous break by the winger.
It was a missed opportunity Celtic would rue as Saints turned the game around before the interval. The equaliser came from a corner forced by David Wotherspoon on the right after another pacy counter-attack. Swanson took the set piece and picked out Watson who climbed above Nir Bitton to power in a header from around six yards which Gordon was unable to divert from its course to the roof of his net.
Henderson had a chance to quickly restore Celtic’s lead but saw his shot held by Clark this time. Saints, playing with increasing belief and purpose, were now just as threatening as the visitors and Wotherspoon was wasteful when he sent a free header wide after being found by another precise delivery from Swanson.
There was a better reward for Swanson’s next cross as it saw Saints take the lead two minutes before half-time. Wotherspoon again rose to try and meet it but when he failed to make contact, his unfortunate marker Boyata inadvertently nodded the ball into his own net.
Celtic made a brisk start to the second half in response and Mackay-Steven, less than impressive on a rare starting appearance, passed up a premium chance to equalise when he scuffed a left foot shot wide from close range.
The controversial nature of the 61st minute penalty which did draw Celtic level at 2-2 merely compounded a sense of grievance in the home ranks which had been provoked by Thomson’s denial of their own spot-kick claim seven minutes later when Swanson went down under a clumsy challenge from behind by Scott Brown.
If that one was debatable, there was no doubt that Thomson made the wrong call when he pointed to the spot at the other end. Tierney’s cross struck Watson on his hip as the defender turned to block it. Even it had hit his arm, which he tucked into his body, it would have a highly dubious claim.
All of which was of little concern to Dembele who had just entered the fray as a replacement for Mackay-Steven. He smashed the penalty high to Clark’s right into the net and it was the cue for the roof to fall in on Saints.
Dembele put Celtic ahead in the 75th minute, beating Clark with a precise right foot finish from 20 yards, then Sinclair’s 16th goal of the season made the victory safe for the champions six minutes later as he shot home from just inside the box after a rapid raid from Roberts.
The gloss was added five minutes from time in extravagant style, Mikael Lustig’s rabona pass complented by Callum McGregor’s back-heeled ball in a move finished emphatically by Dembele to complete his hat-trick.
ST JOHNSTONE (5-3-2): Clark, Foster (MacLean 78), Watson, Shaughnessy, Scobbie, Easton; Paton, Wotherspoon (Alston 70), Swanson (Craig 86); Davidson, Cummins. Subs not used: Mannus, Millar, Smith, Thomson.
CELTIC (4-2-3-1): Gordon, Lustig, Sviatchenko, Boyata, Tierney; Bitton, Brown; Mackay-Steven (Dembele 59), Henderson (McGregor 72), Sinclair; Roberts (Ciftci 86). Subs not used: De Vries, Simunovic, Gamboa, Forrest.