LOS ANGELES —  "McPhever" mania reached a fevered pitch Friday when "American Idol" finalist Katharine McPhee returned to her old high school.

Teenage boys screamed out marriage proposals. Cheerleaders chanted "Go Katharine Go!"

Even Mayor Antonio Villaraigosa showed up to the packed gymnasium at Notre Dame High School to honor McPhee, one of three contestants left on Fox's mega-hit talent contest. The ultimate champ will be announced May 24.

"You make me feel like a winner, regardless of what happens," she told the high-energy crowd.

The 22-year-old brunette — wearing skintight jeans, a black T-shirt and hoop earrings — raced around the gym for an hour singing snippets of songs, breaking out in dance and bear-hugging former teachers.

A sea of posters filled the room, from "Vote for Katharine — Catch the McPheever" to "She's McPhine," "She's McPheerless" and "McPhee is Our Favorite."

Footage of her visit will be shown next week on "American Idol," with hometown segments featuring fellow finalists Elliott Yamin and Taylor Hicks.

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McPhee, the first Los Angeles native to make it big on "Idol," seemed overwhelmed by the frenzy.

"I'm more nervous now than on the show," she said, just before launching into a soulful rendition of "God Bless the Child" — the tune she sang at her original "Idol" audition.

As for fame and the future, McPhee reflected on her past as a singing star in high school and said she missed being in musical theater productions.

"I will definitely go back to that," she said.

A question from an aspiring singer prompted a bit of advice. McPhee said wannabe "Idol" contestants should pick their songs ahead of time and "remember to breathe."

Ninth-grader Amanda Dodge, 15, echoed other students in her support of McPhee.

"I think it's amazing she's here," she said. "Even though she's moving on to a whole new world, it's great to see her recognize everyone who brought her to where she is today."

Dodge dismissed controversy over this week's "Idol" — in which McPhee landed in the bottom two, but favored Chris Daughtry was voted off. Some Daughtry fans have said their votes may have been mistakenly credited to another contestant.

McPhee's 23-year-old sister Adriana, another tall Notre Dame alum, said she was thrilled for her sister, adding she hoped McPhee makes the final cut. To do her part, she voted for two hours for her little sis.

"I feel guilty if I'm not voting!"