Glasgow giants Rangers and Celtic will have to replay their Scottish Cup fifth-round clash after a 2-2 draw at Ibrox ended with both sides reduced to ten men.
Jamie Ness opened the scoring for the hosts in the third minute with his first Rangers goal before Kris Commons, playing his first Old Firm game, drew Celtic level in the 15th minute. Steven Whittaker restored Rangers' lead after Celtic goalkeeper Fraser Forster was sent off for bringing down Steven Naismith in the box.
But Celtic captain Scott Brown made it 2-2 in the 64th minute before, in another twist, Naismith - already booked for a first half foul on Mark Wilson - was sent-off for diving inside the visitors' penalty area. The sides will now meet in a replay at Parkhead on 2 March. Rangers made three changes as Nikica Jelavic and El-Hadji Diouf were handed Old Firm debuts while Daniel Majstorovic recovered from injury to play in the centre of Celtic's defence.
In a frantic start the home side put the Hoops under constant pressure and took the lead in the third minute. Diouf's corner was headed clear to the edge of the box where Ness took a touch before unleashing a curling shot that flew into the net with Forster rooted to the spot.
Just over a minute later Rangers nearly doubled their advantage when Diouf released Jelavic down the left wing and his cross was fired onto the underside of the bar by Steven Davis but bounced out. Celtic began to regain their composure and Commons restored parity in the 16th minute when he slammed Joe Ledley's cut-back past McGregor from 12 yards to score on his Old Firm debut.
Forster saw red in the 38th minute after bringing down Naismith in the box. Zaluska replaced Commons and his first task was to pick the ball out the net after Whittaker sent the Polish goalkeeper the wrong way to bury the penalty in the bottom right-hand corner.
The home side failed to make their advantage count and Brown hauled the Hoops level in the 65th minute. The Celtic captain was given time and space 20 yards out and he curled an angled shot into the far corner past the outstretched arm of McGregor. Rangers should have regained the lead two minutes later when Jelavic beat the offside trap to race clear but there was too much pace on his cross and Davis failed to connect with it.
Substitute Georgios Samaras saw a header cleared off the line before Rangers were reduced to ten men in the 76th minute when Naismith, who had been booked in the first-half for a lunge on Wilson, received a second yellow after referee Callum Murray adjudged he had dived in the box, although there appeared to be slight contact from Charlie Mulgrew. Joe Ledley and sub Kyle Lafferty both came close to sealing a later winner for their sides, who will now meet an incredible seven times this season.