Hoops fans were incensed by two moments of controversy during the second half as they pounded at the Rangers defence in search of a goal.

Thomson is no stranger to controversy and was at the heart of the action in the 13th minute when he booked Barrie McKay of Rangers for simulation as he went down theatrically in the penalty after Jozo Simunovic had cleared the ball.

While that was a brave and correct call there was no justification for the two decisions that went against Celtic during the second half.

Three minutes after the restart Erik Sviatchenko timed his run perfectly to glance a header low and across goal into the net at the far post.

The Celtic defender kept his eyes on the ball throughout the move but for reasons best known to himself Thomson spotted an infringement as 38-year-old Clint Hill fell to the ground in instalments as Sviatchenko redirected the ball into the net.

“I couldn't believe it,” the defender said after the match. “It was a good goal, I got my head on the ball and thought that again I'd scored in this huge fixture.”

Brendan Rodgers added: “I'll need to see the header again but it looked very harsh to me. The one that was disallowed, but again it shows our mentality to bounce back from that.

“They didn't get disappointed, they showed great discipline and eventually got their reward.”

It was incessant pressure from Celtic throughout the second period with Scott Sinclair striking the crossbar in the 66th minute from a free-kick.

As Celtic pushed on in search of the breakthrough the Rangers defence retreated further and further back resorting to more desperate measures to keep Celtic at bay.

Nine minutes from full time Sinclair looked set to put Celtic in front as he positioned himself ready to shoot 12 yards from goal.

When Rangers skipper Lee Wallace came in from an awkward angle and crunched through Sinclair's right leg it seemed certain that Celtic would be awarded a penalty.

Certain to everyone in the stadium except the man that mattered, Thomson. Both sets of players were waiting for the inevitable finger pointing towards the penalty spot but the man with the whistle saw no reason to stop play.

With two minutes left to play Dembele beat Rob Kiernan to a Griffiths pass to book Celtic's final place- and spare Thomson the fury of a week long inquisition into those two decisions.