To date, Universal's Jurassic World is the top-grossing summer title of all time ($1.672 billion), not adjusted for inflation. However, the dinos are now in serious danger of losing the crown to Avengers: Infinity War, the record-breaking Disney and Marvel superhero mashup that is the first summer pic in history to have a shot at nearing $2 billion in global ticket sales after hitting $1.164 billion in its first dozen days. Analysts believe the movie will ultimately gross $1.8 billion-$2 billion.

Among the factors working in Avengers' favor was a last-minute decision to open the film a week early in North America on April 27, giving it three weekends of play with no competition from a rival May tentpole, unheard of in modern times. Summer's second big event title, Deadpool 2, doesn't hit theaters until May 18, followed by Solo: A Star Wars Story over Memorial Day weekend.

"Moving up the release date of was a master stroke of a strategy that paid off in a big way, by rewriting the rules and making the last Friday in April suddenly the jumping off point for the biggest opening weekend in history and, at the same time, giving it a bigger buffer before the release of Deadpool 2," says Paul Dergarabedian of comScore.

Dergarabedian notes that Titanic, another year-end blockbuster, ultimately earned north of $2 billion at the global box office after grossing $1.843 billion in its original run. The rest came from re-release earnings.

Originally, the Avengers threequel was set to open on May 4, the "official" start of summer. But, hoping to minimize spoilers, Disney moved up the release to April 27, timed to Infinity War's international opening.

Infinity War crossed $1 billion at the global box office on Saturday, faster than any title in history. It achieved the milestone in 11 days, compared to 12 days for Force Awakens, from Disney. And in its second weekend, it earned an estimated $112.5 million domestically, the second-biggest sophomore outing behind Force Awakens ($149.1 million).

Overseas, Infinity grossed $162.6 million in its second weekend for an early foreign total of $713.2 million, including a record-breaking Russian opening of $17.6 million.

Box-office analysts surveyed by The Hollywood Reporter predict that Infinity War will ultimately gross at least $1.1 billion-$1.2 billion overseas, noting that it has yet to open in China, where it unfurls May 11 (in 2015, Avengers: Age of Ultron amassed $240 million in the Middle Kingdom).

Domestically, Infinity War is pacing 12 percent ahead of Jurassic World, which topped out at $652.3 million.

"It's all about timing for these box-office behemoths. Avengers: Infinity War is in a nifty spot right now, as it will certainly remain potent until after Memorial Day. That kind of long run is the only way it could eclipse Jurassic World as the top-grossing summer movie of all-time," says analyst Jeff Bock of Exhibitor Relations."Currently, Infinity War is outpacing Jurassic World by nearly $50 million — unadjusted for inflation — which means if it has a great hold next weekend, we could be looking at upwards of $700 million domestically, and maybe even $725 million," Bock continues. "The domination of Disney is unparalleled in modern-day blockbuster cinema. If Walt [Disney] were alive today, he'd probably be holding hands with Stan Lee, instead of Mickey Mouse."

May 7, 12:30 p.m. Updated with additional Titanic information.