While it doesn't officially hit the streets until Monday, One Direction's upbeat new single, [article id="1710570"]"Best Song Ever,"[/article] has hit the 'Net early, leaving fans squealing with delight, calling it "different," "perfect" and ... the "best song ever." "I'm screaming," one fan added.

BEST SONG EVER IS PERFECT IM SCREAMING I KNEW IT WAS GONNA BE GOOD IN MY OPINION IT WILL BE THEIR BEST SINGLE THEY'VE RELEASED

— ashley✝ | 7 days (@poisonIirry) July 17, 2013

The version that surfaced Wednesday opens with a riff that sounds very similar to the Who's "Baba O'Riley" and is all about the guys going out, meeting girls and dancing all night to, you guessed it, the best song ever.

With its stomp-along beat, the song keeps up its lively pace, even if some of the lyrics are a bit unexpected -- in some ways, they pay homage to Wheatus' quirky songwriting on "Teenage Dirtbag," a song frequently covered by the fab fivesome in concert. A memorable moment includes the lyrics, "She said her name was Georgia Rose/ And her daddy was a dentist/ Said I had a dirty mouth/ But she kissed me like she meant it."

Omg best song ever is the best song ever my love for one direction will never fade this is eternal this is my soul

— Tanner (@TannerMurray2) July 17, 2013

The video will be released on the same day as the song. Based on two teases, the clip looks like it's angling for the best video ever prize. In it, the guys play characters inspired by Hollywood movers and shakers.

In a tease released on Tuesday, Niall Horan is dressed up as a fast-talking studio exec named Harvey. On Wednesday, Liam Payne's character was revealed. He'll play Leeroy, a headband-loving, fashion-forward choreographer.

Despite the leak, fans vowed to buy the song when it goes global on Monday. "Best Song Ever" is not only the featured track in their [article id="1709560"]"This Is Us" movie trailer[/article], but also serves as the first listen to their third album, rumored to be released by the holidays.