We knew it was going to happen, and now it has: This weekend, Black Panther will cement its place as the top-earning superhero movie of all time at the U.S. box office.

The current Friday-Sunday estimate of $16.6 million for Black Panther will bring its cumulative domestic total up to $630.9 million (h/t Deadline). That gives it a small-yet-not-insignificant lead over The Avengers, which ended its May-September, 2012 run with a domestic take of $623.3 million.

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It's still early in the weekend, and Black Panther's estimate is likely to shift in either direction. But there's little chance of the current estimate falling by the $7 million it would take to leave Marvel's latest in second place for one more day.

Black Panther's box office success is all the more noteworthy in the context of the Marvel blockbuster it is poised to unseat. The Avengers was Marvel's first major superhero ensemble effort, and it arrived at precisely the moment the Marvel Cinematic Universe reached peak popularity.

Eleven other MCU releases have come and gone since The Avengers dropped, and not one of them — not even the epic Captain America: Civil War smackdown, which included Spider-Man's MCU debut — came close to #1. The Avengers sequel, Age of Ultron, is the next one down on the list, with a total domestic box office of $459 million.

Black Panther did it. Box office lists don't account for inflation, though the six-year gap separating Marvel's top two box office hits makes that much less of a factor here. Especially since Black Panther is only in its sixth week of release and its box office bounty is sure to grow.

The big question now is: How long will this record hold?

The next Avengers movie, Infinity War, is only a few weeks away. The Avengers movies have historically been Marvel's biggest box office performers, and this one is sure to benefit from a number of advantages.

For one, it's a story that Marvel has been building up to since pretty much the beginning of the MCU, when the Tesseract was introduced all the way back during the initial "Phase One" wave of releases.

It's also a major ensemble piece, drawing in heroes (and villains!) from virtually every other MCU movie to date. In addition to the allure of seeing more than 40 familiar faces duking it out on screen, Infinity War benefits from bringing in moviegoers from all corners of MCU fandom.

By extension, Infinity War only benefits from its proximity to Black Panther's release. Even putting aside the far-reaching cultural impact of its majority-black cast and thematically relevant storyline, its critical and commercial success overall represents a high point for the MCU. That wave alone should carry Infinity War to a massive box office.