When the best actress Oscar came calling for Halle Berry, everyone knew there’d be bigger,… When the best actress Oscar came calling for Halle Berry, everyone knew there’d be bigger, better things in store for her.

But for Gabrielle Union?

Berry was set to star in “Deliver Us from Eva,” an update of Shakespeare’s “Taming of the Shrew.” But the pre-Oscar buzz – and the potential salary hike that a win brings – put that at risk.

That’s when it paid to be the backup.

Union landed her first leading role in “Eva,” which opened Friday, thanks to one of her biggest fans, writer-director Gary Hardwick.

“He went to the studio on a leap of faith that he could convince them to give the lead to me,” Union says, taking a break from a full day of promotional duties for Hardwick’s film. He knew he wanted Union if Berry didn’t work out.

“When he started talking to me … I’m like, ‘Oh God, I don’t think I’m ready.’ He just said ‘No, you’re ready, I believe in you.’ … After the first day of shooting, I was like, ‘OK, I got this.'”

You might not know her name, but chances are, you’ve seen her.

Union has been in her share of teen movies and limited release black comedies – “She’s All That,” “Love ‘ Basketball,” “10 Things I Hate About You.”

Her big break came as Isis, the head cheerleader of the inner-city squad in 2000’s “Bring It On,” alongside Kirsten Dunst.

Hardwick met Union on the set, where he was working as one of the script doctors and writing speaking parts for her character.

“Finally, everybody will see what I saw 2 1