NEW YORK – She has one of the world’s most famous faces. He’s a billionaire fashion CEO. And their 5-year-old son is at the center of a bitter, big-money child support fight.

Supermodel Linda Evangelista and ex-boyfriend Francois-Henri Pinault, a French business tycoon now married to actress Salma Hayek, faced off Thursday in a Manhattan family court.

She wants a court to make him pitch in for child-rearing expenses she has tallied at nearly $50,000 a month — for armed bodyguards and a round-the-clock nanny, among other costs.

The trial is offering a public glimpse into the lives of the boldface and beautiful, from the vagaries of a modeling career to the peripatetic lifestyle of a movie star’s child. The first day of testimony included a detailed description of a $12 million mansion and Pinault discussing his brief breakup with Hayek before their 2009 marriage.

Evangelista, the 1980s and 1990s magazine-cover fixture who famously quipped that supermodels “don’t wake up for less than $10,000 a day,” looked on in a demure black knee-length skirt, flower-patterned blouse and tan stiletto pumps.

At one point, she let out a faint, frustrated sigh and raked her hair with her hands when Pinault’s lawyer, David Aaronson, said she was looking for $46,000 a month. While that’s what she said she’s spending on the child, Evangelista’s lawyer said Thursday she isn’t asking for any particular amount.

Although she willingly paid all the boy’s expenses for most of his life, her roughly $1.8 million-a-year income took a major hit last year as a contract with L’Oreal ended, said her lawyer, William Beslow.

“It became necessary for her to go to the bullpen and ask the father for help,” he said. “Ms. Evangelista is not looking to piggyback the lifestyle of Mr. Pinault.”

But Pinault’s camp says the supermodel is doing just that. A potential $46,000-a-month tab is “just ridiculous,” Aaronson said.

Evangelista, now 46, and Pinault, 49, dated in late 2005 to early 2006, though he testified Thursday that the trans-Atlantic couple spent only about seven days together over that time.

Pinault is the chief executive of PPR, which owns Gucci, Yves St. Laurent and other luxury brands. He makes about $4 million annually; Forbes recently estimated the family’s net worth at $13 billion.

On Twitter, Demi Moore is @mrskutcher no more

LOS ANGELES  — Demi Moore is no longer @mrskutcher, in real life or on Twitter.

The 49-year-old actress changed her Twitter name to @justdemi on Thursday.

Moore and Ashton Kutcher, who often used the micro-blogging site to post pictures of themselves and proclaim their love for one another, announced the end of their marriage in November. In April, Moore asked her followers on the site for suggestions for a new handle.

TV personality Piers Morgan suggested, “How about @mrsmorgan?”

Moore said she would “have to get clever” because so many names on the popular site have already been claimed.

Infamous Buckner ball up for sale

DALLAS – The baseball that broke the hearts of Boston Red Sox fans everywhere and turned Bill Buckner into one of the most famous goats in sports history is up for sale.

The ball that rolled through Buckner’s legs in Game 6 of the 1986 World Series between Boston and the New York Mets will part of an auction today. Heritage Auctions said the ball is expected to bring in more than $100,000 at an auction featuring the baseball memorabilia collection of songwriter Seth Swirsky.

“That one ball kind of encapsulates the highest and lowest you can feel in sports at any given moment,” Swirsky said.

Buckner hit .289 with 2,715 hits in 22 years and had more than 100 RBIs in two of his three full seasons with the Red Sox. All of that was overshadowed when Mookie Wilson’s grounder rolled through Buckner’s legs, allowing the Mets to cap a two-out rally with a victory in the 10th inning. The Mets went on to win the series and Boston’s championship drought – dating to 1918 – continued until 2004.

“I think everybody remembers where they were, even if they were a sports fan or not. Everybody seems to remember that. It’s not just a baseball moment. It’s not just a piece of Mets history or Red Sox history but it seems like it was a cultural moment of the ’80s,” said Swirsky, who co-wrote the hit “Tell It To My Heart” by Taylor Dayne, and has multiple hits with Celine Dion, Olivia Newton-John and Al Green.