In one of the most-anticipated performances of the night, George Strait and Miranda Lambert paid tribute to Merle Haggard by singing two of his most iconic songs at the 2014 ACM Awards.

The two singers, who were introduced by Garth Brooks, sang Haggard's first No. 1 hit, 'I'm a Lonesome Fugitive,' and 'Tonight the Bottle Let Me Down,' both released in 1966, as pictures of the Hag through the years were displayed on screens behind them. While more than 30 years are between Strait and Lambert, they showed off impeccable harmony, and blended perfectly together for the songs.

Haggard is the recipient of this year's Crystal Milestone Award. The California native turned 77 today (April 6), making it a birthday he's not likely to forget.

He will be honored again next month with a tribute album,‘Working Man’s Poet: A Tribute to Merle Haggard,' honoring his legendary career. More than a dozen artists, including Brooks, Luke Bryan, Randy Houser and Toby Keith, have contributed songs for the record, which will be released on May 1 on Broken Bow.