"Am I coming out of left field?" Portugal the Man asks on their latest single, "Feel It Still."

Damn straight you are. After 13 years of relative innocuousness, the Portland-based band suddenly has one of the biggest songs in the country.

"Feel It Still," a retro-minded rock'n'soul number from this year's Woodstock album, hit No.1 on the Billboard Top 40 this week. It's also reached the Top 5 of the almighty Hot 100, which takes into account sales, radio play and streaming totals. But those achievements alone doesn't fully illustrate the song's reach. It's also topped airplay charts in six different subcategories, placing it in the company of such pop contagions as Mariah Carey's "We Belong Together," Mark Ronson and Bruno Mars' "Uptown Funk" and "Despacito" by…uh, whoever it is that does "Despacito."

Billboard has deemed "Feel It Still" "the biggest rock crossover hit in five years," reaching a level of omnipresence not experienced by an alt-rock single since Gotye's "Somebody I Used to Know" in 2012.

Portugal the Man's core duo of John Gourley and Zachary Carothers moved from Wasilla, Alaska, to Portland in 2004, and over the next decade built a nice little career for themselves, getting signed to Atlantic Records in 2010. While they've become an alt-rock radio staple in that time, and proved themselves adept at writing hooky, enjoyable songs, the success of "Feel It Still" is something else entirely—it's currently outpacing their next most popular song on Spotify by 148,499,510 plays.

It's especially impressive because "Feel It Still" doesn't feel designed to be a huge hit. While certainly catchy, it doesn't necessarily have a big, "jam it in your ear" chorus. It clocks in under three minutes, interpolates the Motown classic "Please Mr. Postman" and generally sounds like something you might hear over a montage in one of the Austin Powers sequels—not exactly a surefire formula for world dominance in 2017.

So how did it happen? Beats us. We certainly didn't see it coming. Maybe this iPad commercial helped.

Portugal the Man's next Portland show is at Crystal Ballroom as part of 94.7's annual December to Remember concert series. As you might expect, it's already sold out.