Coldplay have shocked the crowd at their Melbourne concert by bringing out a 1980s movie legend to the stage for a surprise cameo.  

Karate Kid  Actor Ralph Macchio took to the stage during the show to help the band perform their song  The Karate Kid, from their new album  Moon Music.

Macchio, 62, lip-synched to frontman Chris Martin’s vocals, before the pair embraced warmly in front of the crowd at the sold-out gig.  

Macchio became a household name in the 1980s for playing Daniel LaRusso in three  Karate Kid films, and more recently has reprised the iconic role in the Netflix series  Cobra Kai.

According to a Coldplay fan account on social media, the footage of the actor’s on-stage cameo will be used as a music video when The Karate Kid is released as a single.

The famous  actor had earlier been spotted in the audience at Coldplay’s Wednesday show at Melbourne’s Marvel Stadium, having flown from New York to attend the gig.

Image credits: X/Sonia Moskowitz Gordon/ZUMA/Shutterstock Editorial