It looks like "Guardians of the Galaxy Vol. 2" is going to keep building on its impressive opening weekend overseas. While the film is already expected to surpass its predecessor domestically, the sequel is now outpacing "Avengers: Age of Ultron," which has the fourth best domestic opening of all-time, in advance ticket sales.

Initial estimates put "Guardians of the Galaxy Vol. 2" opening at $150 million domestically, short of "Age of Ultron's" $191.3 million. However, the upcoming film is looking more and more likely to outperform that estimate in light of its overseas success, Deadline reports. Even if it doesn't break "Age of Ultron's" record, $150 million would still put the sequel well above its predecessor, which opened at $94.3 million before going on to earn $333.1 million in its opening month. The film might also have a bigger debut than "Captain America: Civil War," which made $179 million when it released last year.

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"Its popularity has grown exponentially since the first 'Guardians of the Galaxy' surprised audiences as a monster hit," Fandango's Erik Davis stated as to why the sequel is so hotly anticipated. "The series' visual inventiveness, coupled with the addition of Baby Groot and another fantastic soundtrack in 'Vol. 2,' is fueling even more excitement as Marvel Studios looks to kick off the summer movie season in a massive way."

Picking up just months after the events of Marvel Studios' 2014 hit, the sequel follows the Guardians as they travel throughout the cosmos and struggle to keep their newfound family together, all while helping Peter Quill learn more about his true parentage.

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"Guardians of the Galaxy Vol. 2" opens in the US and Canada on May 5. The movie stars Chris Pratt as Star-Lord, Zoe Saldana as Gamora, Dave Bautista as Drax the Destroyer, Vin Diesel as Baby Groot, Bradley Cooper as Rocket Raccoon, Michael Rooker as Yondu Udonta, Karen Gillan as Nebula, Pom Klementieff as Mantis, Elizabeth Debicki as Ayesha, Chris Sullivan as Taserface, Sean Gunn as Kraglin, Glenn Close as Irani Rael and Kurt Russell as Ego.

Via Deadline