Zenyatta's growing popularity outside horse racing led to her odds getting hammered down to 8-5 for the $5 million Breeders' Cup Classic at Churchill Downs.
The horse with the 19-0 record was made the early favorite in a field of 12 for Saturday's 1 1/4 -mile Classic at the Louisville, Ky., track, where she will try to end her career with one more win.
Zenyatta will break from the No. 8 post against the boys.
"We like that number. It's one of our favorite numbers," said Ann Moss, who owns Zenyatta with her husband Jerry. "It's considered to be a lucky number."
At 6, Zenyatta is the oldest horse in the Classic, which she came from behind to win last year on Santa Anita's synthetic surface.
This time, she'll be running on dirt against an accomplished field that includes Preakness winner Lookin At Lucky, Blame, and Quality Road.
Blame was installed as the 9-2 second choice and will break from post No. 5. Quality Road was third choice at 5-1 and drew the No. 1 post. Lookin At Lucky was the fourth choice at 6-1 and will start from the far outside No. 12 post.
Tennis: Murray advances in Valencia Open
Andy Murray began his title defense at the Valencia Open in Spain with a 6-3, 7-6 (1) win over Spain's Feliciano Lopez.
The top-seeded Briton broke Lopez in the fourth game on his way to taking the first set. He then had to rally from a 4-1 deficit in the second after the Spaniard broke in the fourth game when Murray netted.
But Murray took advantage of one of Lopez's many unforced errors to break back and take it to the tiebreaker, where Lopez simply fell apart.
David Ferrer kept alive his hopes of reaching the ATP World Tour Finals in London later this month as the fourth seed rallied for a 6-7 (3), 6-3, 6-3 win over fellow Spaniard Guillermo Garcia-Lopez.
Novak Djokovic made light work of his opening match at the Swiss Indoors at Basel, Switzerland, with a 6-4, 6-2 win over Ernests Gulbis.
Last year, Djokovic beat Roger Federer to win the title in his Basel debut, and made it six wins in six matches at the tournament on Tuesday.
Djokovic will face Daniel Brands or Jarkko Nieminen in the second round, while three-time champion Federer will meet Janko Tipsarevic after the Serb beat Denis Istomin 6-2, 6-4.
The BNP Paribas Open at Indian Wells will become the first tennis tournament to feature replay technology on all eight match courts in 2011.
The tournament, to be played March 7-20, combines the men's and women's pro tours. Most pro tournaments feature Hawkeye replay technology and video displays on up to three courts, but none have made it available on all eight courts, tournament officials said.
AVP pro beach volleyball files for bankruptcy
The AVP pro beach volleyball tour has filed for bankruptcy protection.
According to papers filed in U.S. Bankruptcy Court in Los Angeles on Friday, the tour said it has less than $184,000 in assets and $4.97 million in liabilities. Among those owed money are Olympic gold medal winners Todd Rogers, Phil Dalhausser and Kerri Walsh.
The AVP had hoped to cash in on the popularity of the sport after the American sweep of the gold medals at the Beijing Games. But the troubled economy scared sponsors and investors away. The tour shut down in August when it ran out of funding. It canceled the last five events on the schedule.
The filing was first reported by the Wall Street Journal.
President of Chivas USA steps down
Chivas USA continued its postseason housecleaning, announcing that President and CEO Shawn Hunter is stepping down less than a week after the club fired first-year coach Martin Vasquez.
Hunter, who joined the team in 2007, will continue to serve the club in an advisory role. Attendance rose in Hunter's first two years with Chivas before plummeting to a near-record low this season when the team won just eight of 30 games to finish 15th in the 16-team MLS.
— Kevin Baxter
Sergio Batista was appointed as coach of Argentina, just over three months after Diego Maradona departed after the country's loss to Germany in the World Cup quarterfinals.
Batista had been the acting coach since Maradona's contract was not renewed in late July.