Two minutes of added time at Hampden. Will there be a late, late winner?

Rangers full back James Tavernier is booked for pulling down Patrick Roberts. Roberts takes the free kick and Nir Bitton heads about a foot wide as Wes Foderingham flies through the air Superman-style.

Rangers want a free kick as skipper Lee Wallace's run is stopped in its tracks by Nir Bitton. Referee Craig Thomson is having none of it as Wallace is sprawled on the turf holding his mouth. Gedion Zelalem replaces Rangers central defender Rob Kiernan.

Tom Rogic replaces the hobbling Stefan Johansen. Can the Australian international create something for Celtic in the final third?

Celtic look to hit Rangers on the counter as Griffiths, Roberts and then McGregor press. Rangers clear for a corner. Roberts takes the subsequent corner but Mulgrew balloons his header over the bar.

Celtic full back Kieran Tierney bombs into the Rangers penalty area but his cross is blocked and Rangers repel the danger.

There are more than a few tongues hanging out now...

Chris McLaughlin
BBC Sport Scotland at Hampden

"The high tempo has gone from the match but Rangers continue to look more dangerous. They continue to dominate a lacklustre Celtic midfield. It's getting to the stage where one mistake could be crucial and costly."

Image source, SNS

Celtic midfielder Stefan Johansen receives a yellow card for a late, sliding challenge on Barrie McKay. With 15 minutes of the 90 remaining - this would go to extra-time and penalties if need be - this pulsating cup tie has slowed slightly. Hardly surprising.

Will a wee bit of magic win it?

Another change and its the ineffective Gary Mackay-Steven who makes way for Callum McGregor who gallops onto the Hampden pitch at a fair pelt.

Richard Wilson
BBC Scotland at Hampden

"Celtic's desire, aggression and intensity were irrepressible at the outset of the second half. It delivered a goal and brought the game back into the balance. Rangers have recovered their poise since then, but neither side has control. It is more cagey and less frenetic, with the sense that the next goal will likely be decisive."

Image source, SNS

Nir Bitton strides forward as Rangers cough up possession and Patrick Roberts shows some snake hips as he attempts to evade a few tackles. The on-loan Manchester City winger then tees up Bitton who fires a wild shot high over the bar. 

Dean Shiels trots off to be replaced by Nicky Law as Rangers boss Mark Warburton shuffles his midfield pack with 25 minutes remaining.

Rangers' dead-ball specialist James Tavernier, chasing a club record goalscoring haul for a defender in one season, sends a free kick straight into the Celtic wall. You can't take your eyes off this cup tie. If you were thinking of heading to the kitchen to stick the kettle on, don't. Your cuppa can wait...

Chris McLaughlin
BBC Sport Scotland at Hampden

"So difficult to predict a winner in this match. Celtic look happy to concede possession to Rangers in their own half but Ronny Deila's side are dangerous on the break. Johansen and Brown not at the races for Celtic today and Roberts has been quiet since his glaring first half miss."

Dominic Ball earns a yellow card after coughing up possession under the close attention of Stefan Johansen. The Rangers man will miss the Scottish Cup final against Hibs, should they win.

Erik Sviatchenko is in a similar position...