In 1989 the Grammy's opened a new category in their awards called "Best Hard Rock/Metal Performance Vocal or Instrument". Metallica were invited to perform at the awards and did so with their song 'One' from the then recently released '...And Justice for All'.
I'll let 'Wikipedia' take it from here...
"Metallica was the favorite to win; however, the award was given to Jethro Tull for the album Crest of a Knave. The result generated controversy among fans and the press, as Metallica was standing off-stage waiting to receive the award after performing the song "One". Jethro Tull had been advised by its manager not to attend the ceremony as he was expecting Metallica to win. The award was named in Entertainment Weekly's "Grammy's 10 Biggest Upsets".
Following the release of …And Justice for All, Metallica released its debut music video for the song "One". The band performed the song in an abandoned warehouse, and footage was remixed with the film, Johnny Got His Gun. Rather than organize an ongoing licensing deal, Metallica purchased the rights to the film. The remixed video was submitted to MTV, with the alternate performance-only version held back in the event that MTV banned the remix version. MTV accepted the remix version, and the video was viewers' first exposure to Metallica. It was voted number 38 in 1999 when MTV aired its "Top 100 Videos of All Time" countdown, and was featured in the network's 25th Anniversary edition of ADD Video, which showcased the most popular videos on MTV in the last 25 years."
Metallica, One, performed live at the 1989 Grammy Awards: