DETROIT (AP) – Shannon Eastin used her left hand to tuck her pony tail under her cap after the national anthem and got ready for work.

She seemed to do her job, which ended by helping to separate St. Louis Rams and Detroit Lions players after some shoving, pushing and shouting broke out following the final play.

Eastin became the first woman to be an official in an NFL regular-season game, working as the line judge in the Rams-Lions matchup Sunday.

“It’s a great milestone,” Detroit coach Jim Schwartz said after his team beat St. Louis 27-23. “But we didn’t think about it all during the game.”

That’s probably just the way she – and the league – liked it.

Eastin is among the replacement officials hired by the league while the regular officials are locked out. Replacement officials are working games for the first time in 11 years.

She became the first female official to work an NFL preseason game last month as the line judge when Green Bay played at San Diego. The Pro Football Hall of Fame has the hat and whistle she used during that preseason game, and they’ll are expected to be displayed in Canton, Ohio.

The 42-year-old resident of Tempe, Ariz. has worked as a referee in the Mid-Eastern Athletic Conference – college football’s second-highest level – and has 16 years of officiating experience. MEAC officials declined comment on Eastin, as did the NFL in the days leading up to the groundbreaking assignment.

“Commenting on individual officials is not something we do,” league spokesman Greg Aiello wrote in an email. “Her place in league history speaks for itself.”

NFL Commissioner Roger Goodell has said having Eastin on the field is a great opportunity for her and the league.

“She’s well prepared for it, and I think she’ll do terrific,” Goodell said last month. “So we’re excited about that.

“And there are more coming, by the way. We’ve been working along this path to try to properly train and prepare a female official, and now we have the opportunity.”