Written and first recorded by Bill LaBounty (US #65/MOR #46 1978).
Other hit versions by Michael Johnson (US #19/MOR #5/CAN #9 1979), Sawyer Brown (US #109/C&W #6/CAN #11 1997).
From the wiki: “‘This Night Won’t Last Forever’ was written by Bill LaBounty and was originally recorded by him in 1978, charting in the lower-third of the Billboard Hot 100. One year later, Michael Johnson covered the song and took it to #19 on the same chart.
“Sawyer Brown charted ‘This Night Won’t Last Forever’ Top-10 on the Country music chart in 1997.”