Their first adventure together as a serious couple involved a battle with Doomsday, a monster of Kryptonian legend. Superman, already familiar to the monster, explained that Doomsday was sealed into a pocket dimension called the Phantom Zone. Seeking preparation against enemies that could match them in power, Wonder Woman asked Hephaestus to forge weapons for them. Later, the Justice League intercepted the arrival of General Zod, another Kryptonian survivor. Superman gave him shelter in the Fortress of Solitude, but the couple discovered their relationship was now public knowledge.
In May 2017, early tracking had Wonder Woman opening with $65–75 million, and possibly as high as $105 million. The film opened Friday, June 2, 2017, across 4,165 theaters and made $38.7 million on its opening day, including $3.7 million in IMAX. It was the biggest single-day gross for a woman-directed film, ahead of the $35.9 million opening Friday of Catherine Hardwicke's Twilight in 2008 and the biggest opening day for a woman-led comic book superhero film, ahead of Ghost in the Shell ($7 million). This included $11 million it made from Thursday previews, also the best start for a film directed by a woman, surpassing Fifty Shades of Grey's $8.6 million which was directed by Sam Taylor-Johnson, and the third-biggest of the year, behind Beauty and the Beast and Guardians of the Galaxy Vol. 2. Of that, $1.5 million came from IMAX screenings.