THIS WAS supposed to be Lynne Abraham's moment, the first televised debate in a mayoral campaign in which she seemed to be losing ground by the day.

The Kimmel Center's stage lights kept the dark money at bay and the 74-year-old former district attorney was temporarily on equal footing with her well-funded adversaries, state Sen. Anthony Williams and former Councilman Jim Kenney.

It was 60 minutes of free TV time for Abraham - but her legs gave out at the 10-minute mark.

She crumpled to the floor - loudly - as Williams was answering the first question of the night, about Mayor Nutter's proposed tax hike.

And if the post-debate buzz means anything, that might have been the sound of her campaign folding, as well.

The sight of Abraham's body hitting the stage drew gasps in the theater, all the way to the media room upstairs. She appeared to have briefly lost consciousness.

"Is there a doctor in the house?" NBC10 anchor and moderator Jim Rosenfield called out to the crowd.

Turns out there was, and Abraham later groused that he wouldn't let her return to the stage - which, it goes without saying, is exactly what she wanted to do. She missed the rest of the debate.

"How'd you like my opening act?" Abraham joked with reporters. "Nothing like fainting on stage."

Abraham, who appeared strong and sharp after the debate, said the collapse might've been triggered by a sudden drop in blood pressure. She said it had never happened before.

"The lights went out," said Abraham, who appeared as puzzled by the incident as everybody else.

Her campaign quickly tweeted out a photo of her giving two thumbs up, and she insisted that she'd be back on the campaign trail this morning.

"I'm embarrassed, but I'm quite well," she said, adding, "The campaign continues."

Except it might not.

Abraham already had been having trouble raising enough money to compete with Kenney and Williams, who, in addition to their own campaign war chests, are being supported by super PACs funded by, respectively, organized labor and billionaire school-choice proponents.

"God bless her. It's a shame. She served the city well for so many years, and she deserves a lot of credit for that," Les Fry, a financial consultant, said after the debate. "Maybe this is just not her time."

Others in the crowd echoed that sentiment over chardonnay and sliders.

"You're tough!" Kenney said when he ran into Abraham. "Stuff happens."

Even if Abraham soldiers on, her path to victory in the May 19 Democratic mayoral primary is probably significantly more difficult. And if she bows out, Williams could take a hit, as well. He is considered the leading African-American candidate. Abraham and Kenney were expected to split the white vote to some degree.

The Inquirer reported over the weekend that a poll conducted by a group backing Kenney showed him in a statistical dead heat with Williams, 26 percent to 25 percent, with Abraham pulling 20 percent. If those votes go to Kenney, game over.

"It's sad, and I'm glad she's OK," Kenney said. "I heard it first. I tried to get to her, but we were tethered to the microphones and I couldn't rip it off to get down. I think Nelson [Diaz] was closer. He could get to her."

In addition to Diaz, a former Common Pleas judge, the other Democratic candidates at last night's debate were former Philadelphia Gas Works vice president Doug Oliver and former state Sen. T. Milton Street Sr.

It was a cordial affair, perhaps muted by concern for Abraham. The candidates discussed tax policy, school funding, crime prevention and job retention, among other issues. NBC10 will air two more televised debates.

Abraham tried to lighten the mood with humor. It could have been worse, she said.

"I fell gracefully," she joked. "I didn't hurt anything."

But all around her were hushed voices, concerned faces and a hint of genuine pity.

"Poor Lynne," a woman at the Kimmel Center's reception table said as the crowd filed out.

For Abraham, a hard-boiled ex-prosecutor known to many Philadelphians as "one tough cookie," those are probably the last two words she ever wanted to hear.