Welcome to LIVE coverage of the Champions League semi-final first leg between Bayern Munich and Barcelona at the Allianz Arena.

There's the final whistle. Have that. Incredible performance from Bayern Munich - tepid from Barcelona - and it will take a miracle to keep Barca in the tournament.

Robben swerves a shot over from the edge of the box... in fact it gets a touch so a corner.

Barca racking up the bookings now - Iniesta sees yellow for a foul on Martinez.

Three minutes of stoppage time to be played.

The brilliant Robben gets a standing ovation as he comes across to take a throw-in on the Bayern right.

Jordi Alba's a lucky man. He frustratedly tosses the ball into Robben's face but only picks up a booking. Mind you, that does rule him of the second leg - also known as 'the rest of Barcelona's Champions League campaign'.

Barcelona sub: Xherdan Shaqiri on for Franck Ribery.

It's party time here as Arjen Robben throws himself into a sliding tackle and fortunately fails to make contact. Steady, Arjen.

Robben sprints away from Alexis Sanchez ho tugs him back and it's a free-kick for Bayern.

The Allianz Arena is absolutely jumping, Bayern Munich have destroyed a team still widely considered the best in the world. Magnificent.

Meanwhile, Bayern have brought on Claudio Pizarro for Thomas Mueller.

Barcelona sub: Bit late now - David Villa on for Pedro.

GUTE NACHT!! Thomas Mueller makes it 4-0 Bayern Munich! Barcelona surely dead and buried. Ribery lays it off to Alaba down the left and Mueller turns in his low cross. What a performance.

Alves is back on his feet and should be OK to continue. Still no subs from Vilanova.

Nearly four! Mueller gets in, but Valdes does well to race out and smother the shot - then Alves stays down after a collision with Schweinsteiger.

All Barca possession, but still they struggle to make inroads. Messi punts a long ball straight at Neuer.

Sanchez takes a tumble inside the box, but referee Victor Kassai tells him to stop being silly and get up. Or at least that's what I think he said.

The visitors are virtually camped out inside the Bayern half. Have they got anything left in the tank?

Barcelona free-kick 40 yards out... into the box where Bartra takes it into acres of space - he must score, but he blazes it over. That was not Barcelona composure there... Bartra not the man you'd want that to fall to.

Barcelona really have to score now, and Messi gets on the ball with a sense of urgency for just about the first time.