As a nationally ranked runner and an Olympic hopeful, Delilah Di Crescenzo is used to being chased — but by other athletes, not by pop singers from Chicago.

That was when Higgenson performed the song on TODAY and told Ann Curry the story of unrequited love that had inspired it.

Di Crescenzo, meanwhile, remained all but anonymous.

A graduate of Columbia University, she had returned to her native Chicago to work.

A good but not great runner in high school and college, she gave the 3,000-meter steeplechase a try in 2006 and found that she was good enough in the grueling race to think about trying to make the Olympic team this year.

Higgenson was smitten and even though she had a boyfriend, he told her he was going to write a song about her.

“I thought he was just being flirtatious and leading me along,” the 24-year-old athlete told Lauer and Vieira.

“I had a boyfriend at the time, so I really didn’t believe him.” Higgenson and his band played the song for years at club dates and concerts, and it became a favorite with their fans.

But it wasn’t until last summer that it broke out into the mainstream and began climbing the charts until it was the nation’s top single.

To pursue that dream, she moved to Conshohocken, Pa., where she trains full-time while working as an assistant track and cross-country coach at Bryn Mawr.

She kept casually in touch with Higgenson, mostly through e-mails and instant messages.

When the song was nominated for a Grammy as Song of the Year, he called and invited her to come to the Feb. With her boyfriend’s blessing, she accepted and found herself in the spotlight.