Dundee United 0-2 Celtic

• Celtic win their 15th Scottish League Cup

• Kris Commons and James Forrest score

• Dundee United captain Sean Dillon sent off

• Tangerines' fifth League Cup final defeat in a row

Celtic overcame dogged Dundee United to lift the Scottish League Cup and earn the first leg of a potential domestic treble.

Kris Commons and James Forrest scored the goals that broke United's resolve.

A little of the spirit of Jackie McNamara's side was lost when they were reduced to 10 men after captain Sean Dillon's dismissal in the 56th minute.

Celtic were leading 1-0 at that point, while Forrest saw a late penalty saved by Radoslaw Cierzniak.

Dundee United set out to be resilient with two natural defenders, in Ryan McGowan and Calum Butcher, and two terrier-like midfielders, in Paul Paton and John Rankin, lining up in front of the four-man defence.

The effect was to close down the space that Celtic's four attackers like to operate in.

Celtic broke in behind the United defence on fewer occasions than might have been expected with Commons and Anthony Stokes playing as the wide attackers and Leigh Griffiths constantly looking to dart in behind the two United centre-backs.

Referee Bobby Madden sends off Dundee United captain Sean Dillon

Ronny Deila's side could still cause moments of alarm for their opponents, though.

Jaroslaw Fojut had to hoist one clearance over his own crossbar, while Dillon needed to be alert to nod Virgil van Dijk's header off the line.

The limitation of United's approach was evident when a rare moment of carelessness by Stefan Johansen allowed Ryan Dow to scurry upfield with the ball. He eluded a series of challenges, but still ran out of space and support before anything meaningful could occur.

United were strong, muscular and stoic, while Celtic kept probing for the delicate, subtle pass. They were handed an opening when Griffiths was cute enough to intercept Callum Morris's pass back, but then from a tight angle could only skew his shot into the side-netting.

It took misfortune and, perhaps, an element of misjudgement, for United's good work to be undone.

James Forrest pings home Celtic's second goal 11 minutes from full-time

Dillon suffered what appeared to be a nasty cut from a stud mark after an accidental collision with Van Dijk. He was off the field for two minutes when Celtic scored, with Commons reacting more sharply than Fojut when his shot was parried away by a brilliant Cierzniak save. Pouncing on the rebound, Commons drilled the ball into the net.

Jackie McNamara was exasperated on the touchline, turning round to yell at his staff while Dillon was still inside the dressing room being treated. The United manager was on the verge of bringing on Blair Spittal - the player was stripped and waiting at the touchline - when Dillon finally reappeared. The damage was done, though, to the scoreline and to United's best hopes of triumph.

They felt momentarily aggrieved when, after surging into the penalty area, Dow was nudged in the back by Scott Brown and went to ground, although a penalty would have been a harsh judgement however much United demanded one.

Celtic could rely on more space opening up after the break, with United having to chase an equaliser. Their cause was further enhanced when Dillon was sent off for a straight-legged challenge on Emilio Izaguirre. There didn't seem any malicious intent, but it was a dangerous enough tackle to merit the dismissal.

The decision irked McNamara, who was eventually spoken to by the referee Bobby Madden.

A second goal was inevitable, though. Morris repelled two shots with diving tackles, before Forrest eventually steered the ball into the net from 20 yards. The Celtic substitute was less composed minutes later, when he missed from the penalty spot after being bundled over by Paul Dixon.

The miss was particularly chastening, since some of his team-mates had wanted him to let John Guidetti take the penalty. The fans chanted for it to be Brown, but at the end of a difficult week for the Celtic captain, he would have taken most satisfaction from lifting the trophy at the end.

And with his team leading the Scottish Premiership and with a Scottish Cup quarter-final replay with Dundee United to come, Brown will hope to have his hands on more silverware by the end of the season.

Efe Ambrose celebrated with Celtic team-mates Leigh Griffiths and Kris Commons

Celtic winger James Forrest won a late penalty but his attempt was saved by United's Radoslaw Cierzniak

Celtic captain Scott Brown received the trophy from Rod Stewart