George Strait and Miranda Lambert honored Crystal Milestone Award winner Merle Haggard with 'I'm a Lonesome Fugitive' at the 2014 ACM Awards.

Strait looked dignified as ever in his usual cowboy hat and suit coat while Lambert spiced things up with a fishtail braid, shimmery silver skirt, and denim shirt.

The King of Country kicked off the song, strumming away on his acoustic guitar and then let Lambert take on the second verse, which she did confidently while playing her pink acoustic guitar. 'I'm a Lonesome Fugitive' was Haggard's first No. 1 hit.

When Lambert and Strait finished up the song, Haggard was invited up to accept the award, which honors his five decades in service to country music. To make the evening even more special, it marked the singer's 77th birthday. He got the best rendition of 'Happy Birthday' ever as all the country superstars serenaded him with 'Happy Birthday.'

He briefly took the mic, saying, "Country music's been great to me all my life and it's great again tonight." Haggard went on to thank those dedicated to his music.