HOT SPRINGS, Ark. (AP) -After throwing $5 million at racing's two female superstars to run in the Apple Blossom Invitational, Oaklawn Park's president got half of what he and the horse racing world wanted to see. Zenyatta is here.

She's the early 3-5 favorite for Friday's 1 1-8-mile race, now worth $500,000 instead of $5 million if both horses had run. Just four challengers - none of whom has won a prestigious Grade 1 race - are taking her on as Zenyatta tries to win her 16th in a row.

That would tie Citation and Cigar's modern mark in unrestricted races. Peppers Pride, who retired last year with a 19-for-19 record, and Hallowed Dreams, who won 16 straight, achieved some of their success in statebred stakes.

``I haven't quite got used to 15 yet, so 16 would be awesome,'' Zenyatta's co-owner Jerry Moss said Thursday. ``I only start getting real nervous about it right before the race. She's relaxed and ready, and that's all you can ask for.''

Rachel Alexandra, the other horse track president Charles Cella tried to lure, isn't here, although her jockey and trainer will be trying to beat Zenyatta with different horses.

Calvin Borel is aboard Be Fair, while Steve Asmussen saddles War Echo.

``Try to beat her, that's all we can do,'' said Borel, who admits he'll be rooting for Zenyatta to win.

``It would be awesome, and then maybe she'll hook Rachel at Churchill.''

That's where Rachel Alexandra is currently training, awaiting her next start. One possibility is a race on Kentucky Derby eve.

Zenyatta won the Apple Blossom two years ago in her dirt debut, beating defending champion Ginger Punch.

``She really burst on the scene there,'' her trainer John Shirreffs said.

Her other 14 wins have come on synthetic surfaces in Southern California, highlighted by beating the boys in the $5 million Breeders' Cup Classic in November.

Last month, Shirreffs-trained Zardana upset Rachel Alexandra in her season debut in New Orleans, a result that played into owner Jess Jackson pulling the plug on his 2009 Horse of the Year running in the Apple Blossom.

``I'm sorry she's not here, it would've been something for the fans to enjoy and get people excited about the game,'' Moss said.

There are reminders of what could have been in Oaklawn's gift shop. A poster featuring both horses hangs on the wall, and large buttons with color photos of both are on sale. Trading cards of each were made up and distributed before the showdown derailed.

``You can go certainly a generation without seeing the quality of these two horses,'' Cella said. ``I'm disappointed for racing and the public. It would've been gangbusters.''

Cella said he expects a larger crowd on Saturday, when Oaklawn's season culminates with the $1 million Arkansas Derby. That race will be shown on NBC, while the Apple Blossom airs on a horse racing cable channel. With just five starters, the track won't offer show wagering on Zenyatta's race.

Zenyatta galloped around the dirt track Thursday for a second straight day. Later, she visited the paddock and then Shirreffs led her into the infield, where a stiff breeze ruffled her mane as she got a close up look at the toteboard and big video screen.

Earlier, a crowd gathered in back of her barn to snap photos as Zenyatta nibbled on the grass after having her legs bathed.

Kenny McPeek wandered over from his nearby barn to take a look.

``She's race royalty,'' said the trainer who'll saddle Noble's Promise in the Arkansas Derby. ``She's all class.''

Moss and his wife Ann had planned to retire Zenyatta after the Breeders' Cup and send her off to a breeding career in Kentucky. But those plans changed in January. The 6-year-old mare showed them she wanted to run, and the Mosses wanted to share her with the public.

Fans have responded. Zenyatta has more than 13,000 Facebook fans, and Shirreffs' videos detailing her life around the barn are popular on YouTube. Fans at her Santa Anita races crowd the rail, wave signs and cheer loudly when she runs.

``It's an emotional thing and it seems to get bigger and stronger after every race,'' Moss said. ``She's such a positive force and you feel it.''

Unlike some of the sporting world's human superstars, Zenyatta is fan friendly.

She's known for putting on a show on race days, prancing in the post parade, pawing the ground, and standing still at the sound of clicking cameras so everyone can get their shot of her dark brown coat and forehead blaze.

``She shows you how to live,'' Ann Moss said. ``She's having a good time, she gives her best, and she's having fun. I wish I felt like that every day. It's a beautiful inspiration for living your life.''

The Mosses are pointing Zenyatta toward the Breeders' Cup at Churchill Downs in October. Jerry Moss said he remains open to a showdown with Rachel Alexandra.