The former Hibernian striker also hit the post in injury time but United held on for their first win against the Glasgow giants since May 2012 as they became just the third side after Hamilton and Inverness to beat Ronny Deila's team in league action this term.United started without Paul Paton as the midfielder started the first of his controversial two-match ban for spitting at Jonny Hayes - a punishment issued despite the Aberdeen man backing Paton's claim he had done no wrong.The standard for a frenetic encounter was set after just 30 seconds when Ciftci was booked for clattering into Scott Brown, and the hosts went ahead after four minutes
Sean Dillon was allowed to attack down the right before cutting the ball inside for Armstrong
The United playmaker tried to find Ciftci but saw Nir Bitton divert his pass into the box, while Efe Ambrose swiped at fresh air to put Celtic in trouble.Ciftci had continued his run and made the most of the Nigerian's blunder as he turned and fired past the helpless Craig Gordon.Celtic upped the tempo further but first they saw Callum Morris make a goal-saving interception after Stefan Johansen knocked a header down for John Guidetti, and were then denied by Rado Cierzniak as the Polish stopper raced from his line to block at Johansen's feet.United were dangerous on the break though and Gordon denied them a second goal with a great one-handed stop from Conor Townsend's drive.Celtic claimed for a penalty on the half-hour mark after Dillon barged into Guidetti but referee Stevie McLean ruled it a fair challenge
Bitton then hit the crossbar just before the break - but the Israeli did not know much about it
Johansen's near-post corner was punched by Cierzniak onto Bitton's head and it ricocheted onto the woodwork
Virgil van Dijk followed up but Dillon was well placed to clear off the line.The crossbar rattled again eight minutes into the second half
Johansen showed his bravery as he won the ball in midfield before sweeping it out left to Anthony Stokes
The Irishman's cross was poor but Dillon could only watch with horror as his miscue bounced up against the frame of the goal before James Forrest put the rebound into the side-netting.Deila hoped to gee up his attack as he replaced Stokes and Guidetti with Scepovic and Kris Commons after an hour.But five minutes later it was United celebrating again
Emilio Izaguirre allowed Ciftci to collect Dillon's throw down in the right corner and did nothing to prevent the Turk rolling into the box.There did not appear to be much on but the United striker stood up a magnificent cross to the far post where Armstrong lay unmarked to squeeze home a header.Commons hit a weak effort straight at Cierzniak while Scepovic saw his close-range strike wrongly ruled out
Izaguirre had chested the ball down for the Serbian from Johansen's cross-field pass but television replays showed Blair Spittal was playing Scepovic onside as he turned the ball home.United nearly had a third as Izaguirre had to block Chris Erskine's header from underneath his own crossbar.Griffiths, who had replaced Bitton, gave Celtic hope as he poked through Cierzniak's legs from Scepovic's pass before smashing a 20-yard strike against the base of the post in stoppage time as United held on
Source : PA
Source: PA