SARATOGA SPRINGS, N.Y. (AP) - Rachel Alexandra will not have it easy when the reigning Horse of the Year takes on four rivals in the $300,000 Personal Ensign Invitational on Sunday at Saratoga Race Course.

The 4-year-old filly was made the overwhelming 2-5 favorite Thursday, but Life At Ten is the 5-2 second choice and comes into the 1 1/4-mile race with six straight wins.

Rachel Alexandra finished second in her first two races this year before winning her next two starts, most recently in the Lady's Secret Stakes at Monmouth Park.

But she has yet to face the likes of Life At Ten, who won the Grade 1 Ogden Phipps Handicap and the Grade 2 Delaware Handicap in her last two starts.

Also entered were Miss Singhsix (10-1) and 20-1 long shots Persistently and Classofsixtythree.

Rachel Alexandra drew the No. 2 post and will be ridden by Calvin Borel.

``I have tremendous respect for Rachel Alexandra,'' said Todd Pletcher, who trains Life At Ten, who leaves from the No. 4 post. ``Taking on Rachel is a very, very tall order, but our filly is doing very well.''

The race will be Rachel's first at Saratoga since beating male horses in last year's Woodward Stakes. That capped an 8-0 record that included victories in the Preakness and the Haskell Invitational and clinched Horse of the Year honors over unbeaten Zenyatta.

Rachel's 2010 campaign opened with a stunning loss to Zardana in the New Orleans Ladies. The defeat was followed by yet another loss, this time to Unrivaled Belle in the La Troienne Stakes at Churchill Downs. The setback ended, at least temporarily, calls for a Rachel-Zenyatta showdown.

Rachel bounced back with a 10 1/2-length win in the Grade 2 Fleur de Lis at Churchill and a three-length victory in the Lady's Secret at Monmouth Park. And now, Rachel's trainer Steve Asmussen believes his star is ready to take on top competition again.

``Her last race was very good, but hopefully it's a building block,'' he said.