A trio of R-rated films enter the Labor Day weekend frame as the biz hopes there’s still a chance that summer box office totals could surpass last year’s record-setting number.

Warner Bros.’ femme-driven “Going the Distance,” from New Line, leads the pack at 3,030 locations, while 20th Century Fox looks to entice mostly male moviegoers with its Robert Rodriguez-helmed “Machete,” launching today at 2,669.

Focus Features kickstarted the holiday weekend with the Wednesday bow of George Clooney thriller “The American,” which grossed a solid $1.7 million from 2,721 on its opening day. It expands this weekend to 2,823.

The long weekend typically marks a slower sesh at the box office, and with B.O. experts predicting all three wide releases to debut in the teens — especially given the ratings — this year’s overall summer totals could have trouble reaching the $4.34 billion earned through Labor Day 2009.

Still, with an extra week during the same period last year, studios aren’t complaining too much about the 2010 summer perf.

Meanwhile, overseas auds should continue to embrace more of the same, as domestic holdover titles expand to major foreign markets.

Warner’s “Inception,” which has already posted a standout $387 million internationally, launches in China this weekend, while Fox widens its re-release of “Avatar,” expanding the pic to markets like France and Germany.

Last weekend, the “Avatar” re-release bowed in 14 territories and struggled to rekindle much enthusiasm, grossing $4.5 million internationally. Domestic debut tallied $4 million at 812 locations.

Among the frame’s new entries, “Going the Distance,” toplining Drew Barrymore and Justin Long in the story of a couple in a long-distance relationship, is the only pic this weekend to go day and date, though mostly in smaller markets, including Thailand and Venezuela.

Pic’s domestic rollout should see a healthy turnout from its core demo of females 17-40, while males will tag along for the ride. Romantic comedy is the first narrative pic from Nanette Burstein, who directed docus such as “American Teen.”

“Machete,” based on the fake trailer in “Grindhouse,” is gathering buzz from mostly male auds, and fans of Rodriguez star Danny Trejo could help boost word of mouth to attract wider auds. Pic has been heavily promoted since Comic-Con with stunts such as a Machete-themed taco truck roaming the streets.

Last year’s holiday frame saw a similar demo derby, with Fox’s femme-driven “All About Steve,” toplining Sandra Bullock, pitted against the testosterone-heavy “Gamer,” from Lionsgate. Four-day totals for “Steve” reached $14.1 million vs. $11.2 million for “Gamer.”

“The American,” from “Control” helmer Anton Corbijn, could play best to femme fans of Clooney, but men may turn out for the pic’s international espionage theme.

Focus said there’s clearly an appetite for smart adult fare over the long Labor Day sesh.

Closest comparison is drama “The Constant Gardener,” which Focus likewise opened on the Wednesday before Labor Day in 2005. That pic, without the benefit of Clooney, debuted on fewer screens (1,324), grossing $929,829 opening day. “Gardener” totalled $12.7 million in its first six days of release.

The frame’s soph entries, “The Last Exorcism” and “Takers,” had higher-than-expected debuts, which should help in repeat frames. “Takers” bowed to $20.5 million; “Exorcism,” $20.4 million.

In limited release, Music Box launches today the second installment in the French-lingo “Mesrine” series, “Public Enemy.” Pic will go in the same number of locations as last week’s “Killer Instinct,” which earned $152,873 from 28 screens.

Chinese helmer Zhang Yimou’s “A Woman, a Gun and a Noodle Shop,” from Sony Pictures Classics, bows at five locations in New York and L.A. Pic is a remake of the Coen Brothers’ 1984 neo-noir “Blood Simple.”