Disney’s “Pearl Harbor” fought off a sneak attack from DreamWorks’ surprisingly leggy “Shrek” to capture the box office flag over Memorial Day weekend with an estimated $75.1 million.

That repped the biggest four-day opening ever for a non-sequel, second in the record books only to a 1997 Memorial Day perf of $90.2 million for Universal’s “The Lost World: Jurassic Park.”

It appears the WWII actioner’s debut was cut into by a limit on the number of shows per day given the pic’s nearly three-hour length and a boffo four-day estimated gross for “Shrek” at $54.2 million.

On the other hand, “Harbor” managed to sell out an impressive 85% of its auditoriums, as Disney sent 6,000-plus prints of the Jerry Bruckheimer-Michael Bay epic to 3,214 theaters.

“As we got closer to the opening day, we realized we couldn’t turn over as many show times as we might have liked, especially in the smaller markets,” producer Bruckheimer said. “But what I like about this film is that it really plays in the heartland. So it should be around for a good, long while.”

The “Harbor” aud was split evenly between moviegoers over and under 30, and it skewed slightly male. With the pic capturing such broad demos, Disney expects the $140 million production to sail far.

“I think it’s going to take another weekend or two to tell for sure,” said Dick Cook, chairman of the Walt Disney Motion Pictures Group. But “we couldn’t be more thrilled” about the pic’s performance so far, he added.

The bow was “nothing short of spectacular,” distrib boss Chuck Viane enthused. “I haven’t ever seen so many sellouts,” Viane said. “I just wish we had one more show a day.”

“Harbor” stars Ben Affleck, Josh Hartnett and Kate Beckinsale as lovers caught in a romantic triangle amid the military mayhem. Pic’s big bow — biggest ever both for Bruckheimer and his repeat collaborator, helmer Michael Bay (“Armageddon,” “The Rock”) — came despite largely negative reviews.

Industrywide, the holiday-stretched frame appeared to run out of steam at about $183 million. The four-day estimate fell just short of matching the record $184 million in weekend grosses set in the same frame last year, when “Mission: Impossible 2” opened at $70.8 million.

“If there’s some bad weather around the country, we still have a real good shot at breaking the record,” ACNielsen EDI veep Dan Marks noted Monday morning.

In a year-to-date comparison, 2001 is about 6% ahead of last year, according to EDI data.

‘Mummy’s’ money

No. 3 pic in the latest frame was U’s action sequel “The Mummy Returns,” which grossed an estimated $19.1 million to push cume to $170.7 million in less than four weeks. That compares with an entire domestic run of $155.3 million for 1999’s “The Mummy.”

“Our hopes were always to out-gross the original,” U distrib prexy Nikki Rocco said. “With this one, we’ll get to $200 million-plus.”

Sony’s Heath Ledger starrer “A Knight’s Tale” rode to No. 4 in its third weekend with another $9.3 million in estimated four-day B.O. for a $44.5 million cume. And Warner Bros.’ Jennifer Lopez-as-cop romancer “Angel Eyes” witnessed a second-weekend gross of $6.3 million, good for fifth place and an $18.6 million cume.

No other wide bows were skedded for the holiday weekend, but a couple specialty pics posted sturdy limited openings.

Smiles for ‘Cried’

Universal Focus execs were shedding no tears as “The Man Who Cried,” a drama about civilians in wartime Paris, grossed an estimated $131,000 in 11 major-market theaters for an impressive $11,909 average.

Sony Classics’ Mandarin-language “The Road Home,” tale of a son returning home for his father’s funeral, unspooled in six Gotham and L.A. locations to an estimated $71,411, or $11,902 per venue.

And IFC’s “Our Song,” a drama about a trio of Brooklyn femmes, grabbed an encouraging $18,747 from a single Gotham location.

Twentieth Century Fox’s “Moulin Rouge,” the edgy musical starring Nicole Kidman set to bow wide next weekend, grossed $254,000 as it again sold out a theater each in L.A. and Gotham. And Artisan’s Netco docu “Startup.com” also continued strongly, with another $212,000 in 24 major-market engagements for a robust $8,833 per-venue average.

Two other wide releases are also set for next weekend. MGM opens Martin Lawrence-Danny DeVito laffer “What’s the Worst that Could Happen?,” while Sony/Revolution Studios unleashes Rob Schneider starrer “Animal,” an effects-driven laffer.