The two leading ladies of American racing return to action Saturday, with 2009 Horse of the Year Rachel Alexandra making her season debut in New Orleans and undefeated Zenyatta revisiting the scene of her Breeders’ Cup triumph in California.

If all goes well, the filly and the mare are scheduled to face each other for the first time on April 9 in the $5 million Apple Blossom Invitational at Oaklawn Park in Arkansas.

But first they’ll have to contend with members of their own gender. Rachel Alexandra takes on four rivals in the $200,000 New Orleans Ladies’ Stakes over 1 1-16 miles on the dirt at the Fair Grounds. She’ll carry 123 pounds — two to six more than the others in the race that goes off at 6:15 p.m. EST.

About 25 minutes later, Zenyatta faces eight fillies and mares in the $250,000 Santa Margarita Handicap over 1 1-8 miles on Santa Anita’s synthetic surface.

“I know it sounds funny,” her Hall of Fame jockey Mike Smith said, “but I really think she’s getting better.”

Zenyatta, who beat the boys in the $5 million BC Classic in November on the same track, will carry high weight of 127 pounds — 12 to 19 more than her rivals.

That’s because the race conditions call for the weights to be based on age and past performances. The 6-year-old mare is undefeated in 14 career starts, easily making her the class of the field and the 1-9 morning-line favorite.

The weights were assigned by Santa Anita racing secretary Rick Hammerle to level the playing field, entice some competition for Zenyatta, and make it an attractive betting proposition.

“The better horses carry more weight and the least accomplished carry less,” Hammerle said. “Obviously, Zenyatta is the best horse to come along in a long, long time, so she’s carrying more weight.”

He compared Zenyatta’s weight impost to handicapping Kobe Bryant in a game of one-on-one, with Bryant needing to score 20 points and his competitor getting 15 from the start.

“If I only have to score five and he has to score 20, I’ve got a shot,” Hammerle said, adding that such a setup would attract bettors. “All of a sudden you say, ‘This guy played a little in high school, he’s getting 15 points. Maybe I’ll put $5 on him.'”

Zenyatta has carried 123 pounds in her last three starts. The most weight she ever ran under was 129 pounds in last year’s Vanity Handicap at Hollywood Park, where she won by 2½ lengths.

“She’s a big mare,” Smith said. “She carries the weight very well, so hopefully it won’t bother her too much.”

Zenyatta is the only winner of a Grade 1 race — the sport’s highest level of competition — in the Santa Margarita. The more realistic goal for everyone else would seemingly be to place in a Grade 1 and earn runner-up money of $50,000. The winner gets $150,000. Four of her competitors are listed at 50-1.

“There can’t be anyone going in there thinking they can beat Zenyatta,” said Ben Cecil, who trains 12-1 shot Gripsholm Castle. “The spread has given us all an outside chance. Zenyatta’s not getting away with it easy, but having said that, she’s pretty good.”

In New Orleans, jockey Calvin Borel figures to have Rachel Alexandra racing near the front, while Zenyatta and Smith will sit at the back of their field waiting to unleash her trademark run.

“It’s just incredible what she can do,” Smith said. “When she turns it on, whether you go slow, moderate or quick, she’s got such a turn of foot, she covers so much ground when she does it. She seems to make up a couple lengths in a jump or two.”

Zenyatta comes in off a four-month layoff, having rallied from 13 lengths back to win the 1¼-mile Classic by a length against a deep field of males in her last start.

“She’s a little heavier now, maybe 20 to 25 pounds heavier, than she was for the Breeders’ Cup here,” trainer John Shirreffs said. “You’d expect that, because she hasn’t run since then. She looks like she’s on top of her game right now.”

Now a 4-year-old filly, Rachel Alexandra hasn’t run in six months, having capped her 8-0 campaign last year with a victory against older males in the Woodward Stakes on Sept. 5. She also beat the boys in the Preakness and Haskell Invitational.

Smith hopes he can watch Rachel Alexandra’s race before he heads out to ride Zenyatta.

“I’m a big fan of hers, too. I hope she runs well and we do meet in Arkansas,” he said. “It’s going to be one of the most watched races in history if we’re both lucky enough to get there.”