Three weeks after leading Paramore to one milestone, rising single “Ain’t it Fun” has achieved another.

By ascending to #21 on this week’s Billboard Hot 100, the critically acclaimed single becomes the biggest hit of the pop-rock band’s career.

That honor was previously shared by “The Only Exception” and “Still Into You,” which both peaked at #24 on Billboard’s definitive sales chart.

And the song’s climb might not yet be over. Still gaining airplay at Top 40, “Ain’t it Fun” is on the cusp of becoming one of the format’s Top 10 most-played.

A hot digital seller, the track is also flirting with an entry into the Top 10 of iTunes’ overall single sales chart. It was #12 at press time.