Dundee United are unravelling now as Paul Dixon clambers all over the back of James Forrest.

Celtic make their final change, with Liam Henderson joining the fun and Nir Bitton trudging off.

Chris Erskine tries his luck for United but cannot find the target with his shot.

Celtic have one hand firmly on the cup now as United are exposed by a swift attack. Callum Morris makes a great sliding challenge on John Guidetti then Stefan Johansen's follow-up is blocked before James Forrest picks his spot with a calm finish from 18 yards.

Dundee United win a corner. They need to make the most of these opportunities. goalkeeper Craig Gordon does well to get a paw on the ball in a congested penalty area and Celtic clear their lines.

Richard Wilson, BBC Scotland at Hampden

"Celtic's periods of dominance are now only sporadically interrupted by United counter attacks. The substitute Henri Anier has pace, but no ability to hold up the ball and allow play to build around him. At this stage, and with United beginning to tire, the expectation is of a second Celtic goal."

Dundee United brought on Chris Erskine a few minutes ago, with midfield scrapper Paul Paton withdrawn.

Virgil van Dijk again causes problems for the United defence, getting on the end of Stefan Johansen's corner but Callum Morris is strong in the challenge and the ball drifts wide.

Celtic keep coming and a nice dummy from John Guidetti creates space for Anthony Stokes to run into but the forward is wayward with his shot from 20 yards.

We're at 70 minutes now and Dundee United are hanging on at 1-0 down. It should really be 2-0 as Virgil van Dijk flashes a header over from six yards, Stefan Johansen having provided the cross.

A double change from Celtic as Leigh Griffiths and Kris Commons make way for John Guidetti and James Forrest.

Celtic striker Leigh Griffiths whips in a demonic cross from the left and Stefan Johansen gets in front of his man at the near post but his close-range touch takes a lick of paint off the woodwork.

Striker Leigh Griffiths collects a lovely pass from Stefan Johansen but his touch his heavy and a good chance for Celtic to double their lead disappears.

Remember, it was nine v 10 last weekend with these two and United held on for a draw. They did, however, score first on that occasion.

Depleted Dundee United make a change up top as Henri Anier replaces Mario Bilate.

Tempers are fraying as Dundee United midfielder Paul Paton is cautioned for catching the ankle of Efe Ambrose with a late lunge.

Image source, SNS Group

Uphill. Task. Dundee United are down to 10 men as skipper Sean Dillon hammers into Emilio Izaguirre with his studs up. A textbook reckless challenge...

Dundee United striker Mario Bilate was quiet in the opening 45 minutes but he's started the second half in lively fashion as he outmuscles Jason Denayer on the break. He has to cut back to avoid Virgil van Dijk though and his deflected shot is well handled by Craig Gordon.

Richard Wilson, BBC Scotland at Hampden

"Celtic's one-goal advantage provides them with control of the match as well as the scoreline. United need to be more progressive and creative if they are to find the means to equalise, and that will leave space for Celtic to attack into. United also need more involvement from Bilate, while Johansen remains Celtic's beat source of craft and guile."

Anthony Stokes slips behind the Dundee United defence to poke the ball across goal and a diving Leigh Griffiths is inches away from connecting with his head.