MOSCOW (AP) — For a lap, teenager Mary Cain was right there, near the front of the pack and on the heels of teammate Jenny Simpson.

The 17-year-old — youngest ever in a 1,500-meter final at the world championships — was thinking big Thursday night.

A top-five finish? Even bigger than that.

A medal? Bigger.

Cain really, really wanted that stuffed animal organizers hand out to the medalists. That's the prize she had her eye on.

Only she faded and faded as the race went on, until she was running last at one point. Cain rebounded to finish 10th out of 12 runners in a race won by Abeba Aregawi of Sweden, with Simpson taking second. Disappointment for Cain, though, soon turned to anger, before transforming into giddiness.

"Hey, I got a uniform out of this," Cain said. "So, I'm happy."

The effervescent Cain may not have medaled, but it hardly dampened her enthusiasm. Using words like "jeez" and expressions such as "no way!" she sounded like, well, a teenager.

She even pretended the women taking the line against her were teens, too.

"I was like, 'There's no way I'm letting 16-year-olds beat me,'" said Cain, who's from Bronxville, New York "Of course, most of them are like, 20-something. I think this was a good experience. Obviously, I'm not complaining."

She certainly made an impression on Simpson, who didn't know Cain at all before the competition but spent some time with her this week analyzing races.

"I have been told on occasion that I can be intimidating, which I don't think is true at all," said Simpson, who relinquished her 1,500 crown after winning two years ago in South Korea. "I hope I'm an approachable person, but I haven't really seen her much or gotten a chance to speak positively into her life."

It's been quite a whirlwind last few years for Cain, whose rapid rise and record-setting races have drawn frequent comparisons to Mary Slaney. Cain even trains with Alberto Salazar's group, which also includes Mo Farah and Galen Rupp.

"Alberto was talking to me one day, and he said, 'No offense, but it's time for your records to be broken,'" Slaney said in a recent phone interview. "Mary sounds like a pretty neat kid. I think it is time we have someone come along that's ready to make the next leap for Americans."