Barcelona's Lionel Messi celebrates scoring the first goal during their Champions League semi final first leg match against Bayern Munich at Camp Nou, May 6, 2015. [Photo/Agencies]

BARCELONA - Cometh the hour cometh the man and Barcelona's Lionel Messi stepped up to the mark in sensational fashion on Wednesday.

As a high-quality and compelling Champions League semi-final first leg against Bayern Munich looked to be heading for a goalless draw, the Argentine maestro took centre stage.

After 77 minutes of toil trying to break down a disciplined Bayern defence and the world's best goalkeeper in Manuel Neuer, Messi struck like a cobra.

The German champions lost possession on the left, Dani Alves picked up the ball and passed it to Messi who sent a left-foot shot fizzing into the bottom corner from 20 metres.

Three minutes later, Messi gathered the ball and turned on the after-burners to leave Jerome Boateng for dead before dinking a precise shot nonchalantly over Neuer, his record 77th goal in Europe's premier club competition.

"When Messi is inspired he is unstoppable and tonight he showed his talent again," Barca defender Gerard Pique told Spanish television.

Barcelona coach Luis Enrique added: "He is on another level but also look at how he ran in defence. If we were not a team then we would not be able to do anything. We were very effective."