With her hair tucked under her black cap, Shannon Eastin made history Thursday night as the first woman to referee a National Football League game.

Before taking her place as a line judge for the pre-season game between the San Diego Chargers and Green Bay Packers, she acknowledged at news conference Tuesday afternoon that she was a bit of a pioneer.

"I would say probably most of the way, to some degree, yes. Even in my previous experience in judo, I did a lot of things that were first there," Eastin said.

Eastin threw five flags Thursday night, according to The Los Angeles Times, including a "significant fourth-quarter call that replays justified, flagging San Diego cornerback Greg Gatson for pass interference because he ran into Green Bay receiver Dale Moss."

She also intervened to calm a post-play confrontation between Gatson and three Packers, The Times reported.

Some say Eastin, 42, of Tempe, Ariz., got her shot to wear the iconic black-and-white-striped referee jersey not because she earned it but because she crossed a picket line. No matter how you look at it, however, Eastin was grateful for the opportunity.

"I'm excited," she said Tuesday. "Every step is hope that I can continue to show it really doesn't matter; male or female, as long as you work hard."

One difference is that her hat and whistle will be taken to the Pro Football Hall of Fame in Canton, Ohio, to commemorate the milestone.

Eastin got her chance in part because the league's regular officials are locked out in a labor dispute. It's unclear whether she will be able to stick in the NFL after a new deal is signed.

"My guess would be that she said, 'Yes, I'm going to cross the picket line. Yes, I'm going to go and do something that could break the union, but this is my chance,'" sports columnist Christine Brennan said.

Eastin is no rookie to the game. She enters her 17th season as a football official. She spent the past four seasons refereeing college football in the Mid-Eastern Athletic Conference, which fields 13 teams competing in the Football Championship Subdivision, formerly known as Division 1-AA.

"For me, this is my dream coming true," said Eastin, director of officials for the Arizona Charter Athletic Association and owner of SE Sports Officiating. "I'm honored the NFL has chosen to place me in this position. I feel blessed and excited.

This isn't the first time Easton has been in the spotlight. She is a world-class judo athlete, earning six national judo championships. At age 11, she was the youngest judo athlete to ever be accepted to train at the U.S. Olympic Committee's training center.

There has always been pressure on Eastin in the football officiating profession, but she said she plans to take negative criticism or potential backlash from an unpopular call in stride.

"Knowing that I'm a female in a man's world, I've always put the most pressure on myself," she said. "Pretty much everything I do is going to be magnified. I know what I signed up for.

"I have to be bigger, stronger, know that I understand the rules. I have to do things even better than the men that are working. And I'm OK with that."

To keep herself focused, Eastin tends to stick with the people who want to see her succeed rather than focus on those who don't want to see her succeed, or think that she can't simply because she's a woman. Standing at only 5-foot-5, she had some pretty big shoes to fill in this male-dominated sport, but Eastin believed she was ready.

"I'm a realistic type person," she said. "I know what's realistic for me. It's not realistic for me to play in the NFL, but it is realistic for me to officiate."

Despite all the publicity she has received for her major accomplishment as the first female NFL referee, she remained humble about the entire situation.

"I just want to be unnoticed out there," Eastin said, "even though I know everyone's watching."