Dundee United and Celtic have it all to do again after a controversial 1-1 William Hill Scottish Cup quarter-final tie at Tannadice which saw three red cards and two penalties, one missed.

Referee Craig Thomson sent off Hoops defender Virgil van Dijk and United midfielder Paul Paton after only nine minutes but it looked like it was a case of mistaken identity with regards to the home player, as it had been Calum Butcher who had tangled with the Dutchman.

United striker Nadir Ciftci, who might have been punished following his reaction to a bruising challenge by Hoops skipper Scott Brown which sparked the two dismissals, scored with a penalty in added time in the first-half after Aidan Connolly appeared to go down without much help in the penalty area under pressure from Parkhead forward Anthony Stokes.

Three minutes after the break, United defender Paul Dixon was sent off for blocking a goal-bound drive by Leigh Griffiths, with Terrors keeper Radoslaw Cierzniak saving the subsequent penalty by the Hoops striker, who made amends in the 71st minute when he headed in a Stefan Johansen cross.

This was meant to be the first of a three-match trilogy between the two clubs, who meet in the Scottish League Cup final next Sunday before a Scottish Premiership meeting the following week, but now a replay at Celtic Park will take place on March 18.

The game burst into life when Brown and Ciftci clashed in a tackle - the United forward appeared to leave his foot in - followed by Van Dijk and Butcher who became angrily entwined by their legs on the ground, both trying to escape.

Ciftci was only playing after winning his appeal against a two-match suspension following his clash with Inverness defender Gary Warren last month.

Paton was one of the first on the scene as a melee broke out but when it calmed down, referee Thomson, after speaking to assistant Graham Chambers, dismissed Paton and van Dijk, leaving the United player fuming and everyone in the ground in some confusion.

The game became increasingly tetchy and disjointed before some football broke out just before the break.

In the 42nd minute Cierzniak made a decent save from Johansen's low drive at the expense of a corner which came to nothing.

Moments later, at the other end, Butcher's shot was redirected on to the post by United midfielder Ryan Dow before Celtic broke and Stokes hit the post with only Cierzniak to beat.

There was further woe for the Irishman when Thomson deemed he had tripped Connolly as he burrowed his way into the box, with Cifcti slamming the penalty past Parkhead keeper Craig Gordon.

An early penalty in the second-half was less controversial.

In the 48th minute Thomson no option but to point to the spot when Dixon used his hand to prevent Griffiths' shot from 10 yards levelling the scores.

Cierzniak, however, threw himself to the left to parry Griffiths' spot-kick with Tannadice stopper Jaroslaw Fojut blocking James Forrest with the rebound for a corner which again the home side survived.

Connolly came off for defender John Souttar as Celtic swarmed around the United box looking to equalise.

Cierzniak made a good save from a Stokes drive before he made way for John Guidetti, with Chris Erskine replacing Dow.

The Parkhead side's pressure paid off when Griffiths headed Johansen's cross past the United keeper and into the far corner.

The visitors increased their control on proceedings.

With the home side hanging by a thread, Celtic midfielder Nir Bitton fired a long-distance drive just past the post but United saw out five added minutes although the ramifications from this game will go all the way to League Cup final at Hampden next Sunday.