Watch: Metallica pay tribute to Black Sabbath on final night of M72 World Tour

Metallica wrapped up their M72 World Tour in London on Sunday (July 5) with a tribute to Ozzy Osbourne and Black Sabbath during their set.

The moment happened during the band's regular "Kirk and Rob Doodle", where Kirk Hammett and Robert Trujillo usually play a quick cover linked to the city they're performing in. This time though, London got something a bit more personal.

Before they kicked into the music, Trujillo held up a fan-made sign he'd just been handed that read, "Do It For Ozzy."

"A year ago today was a very important event. Back to the Beginning, Black Sabbath and so many other people. Someone just gave me this right now and it's pretty powerful," he told the crowd.

"It says, 'Do It For Ozzy.'"

"So we've got a little bit of a mashup here. Oh yeah. Ozzy, we love you and we miss you brother. So let's do this. Let's figure it out. It's a mashup of our two favourite bands and you're gonna get it in a minute."

The pair then launched into a mash-up of Black Sabbath's 'Electric Funeral' and the Sex Pistols' 'Holiday in the Sun', giving fans a tribute that perfectly matched up on the one year anniverary of the huge farewell gig.

Metallica were part of the stacked line-up that day in Birmingham's Villa Park, performing 'Hole in the Sky' and 'Johnny Blade' in honour of the metal pioneers. Trujillo's mention of the event before the performance made it clear this wasn't just another cover, it was a genuine thank you to one of the bands that helped shape Metallica's sound.

Metallica have never been shy about wearing their Black Sabbath influences on their sleeves. They've covered Sabbath classics like 'Paranoid', 'Iron Man', 'Hole in the Sky' and 'Sabbra Cadabra' over the years, but this marked the first time they'd performed 'Electric Funeral' live.

For a band that helped shape heavy metal, it felt like a fitting salute to one of the greatest to ever do it.