Thiago Alcantara’s electric second-half double helped Bayern Munich thrash Arsenal 5-1 in the first leg of the Champions League last 16 on Wedneday.

Munich opened the scoring early on thanks to Arjen Robben’s fantastic 20-yard strike, before Alexis Sanchez levelled on the half hour.

The Gunners were coping well with their Bavarian opponents until centre-back Laurent Koscielny was forced off injured – initiating an Arsenal capitulation.

[READ MORE: Arsenal thrashed by Bayern Munich – as it happened]

Poland international Robert Lewandowski headed Carlo Ancelotti’s men in front, before Thiago slotted home from close range to double the lead.

Thiago then netted a deflected effort from the edge of the box just ten minutes after Lewandowski’s to cap a remarkable comeback, before Thomas Muller – fresh off the substitutes bench – slotted home a fifth.

The result left a limp Arsenal side reeling after a heavy first leg defeat which left their Champions League ambitions hanging by a thread.