LOUISVILLE, Ky. (AP) -Trainer Steve Asmussen still thinks the world of Rachel Alexandra, even if she isn't as quick as she was last year.

The superstar filly lost her second straight race on Friday, by a head to Unrivaled Belle in her return to Churchill Downs for the $400,000 La Troienne Stakes.

``We need to pet on her, let her realize who she is - that she's still the 2009 Horse of the Year - and we're very proud of her for that,'' Asmussen said. ``But on a racing standpoint, to win you've got to go faster.''

Rachel Alexandra lost again as the heavy favorite. This time, she was sent off at 1-5 odds by a crowd who cheered her introduction as she bucked in the post parade.

She was upset as the 1-20 favorite in her season debut in New Orleans last month, causing co-owner Jess Jackson to pull her out of a highly touted matchup with female rival Zenyatta in the Apple Blossom at Oaklawn Park.

``The defeat last time put a whole lot more pressure on this one,'' Asmussen said.

Zardana, Zenyatta's stablemate, won by three-quarters of a length in New Orleans with Rachel second. The California-based mare was the 5-1 second choice Friday, but finished fifth in the six-horse field.

A year ago to the day, Rachel Alexandra won the Kentucky Oaks by an astonishing 20 1/4 lengths, then went on to beat the boys in the Preakness Stakes and win her next four starts. She was voted Horse of the Year over Zenyatta, who is 16-0.

``She's not quite there yet,'' said Jackson, who was on hand. ``We don't mind losing as long as she's healthy. When she came out of the race, she was perfect. We love her anyway.''

Zenyatta has won both her starts this year, in her home state of California and in the Apple Blossom. Her next start could be June 13 in the Vanity Handicap at Hollywood Park.

Asked if Rachel and Zenyatta would eventually meet, Jackson said, ``Of course, but she's not ready. Zenyatta may be.''

Jackson was unsure when Rachel Alexandra would make her next start, saying only, ``She's not going to retire.''

Unrivaled Belle covered 1 1-16 miles in 1:42.97. She paid $20.80, $3.40 and $2.80 at 9-1 odds. Rachel Alexandra returned $2.10 and $2.10, while Peru-bred Morena paid $4.80 to show.

Asumussen said Rachel Alexandra showed improvement off last month's loss.

``I was definitely a lot more positive today with how she acted, how relaxed she was and how steady it was,'' he said. ``There was a lot of positive in that, just not quite as quick.''

Ridden by Kent Desormeaux and trained by Bill Mott - both Hall of Famers - Unrivaled Belle won her second straight stakes. She won the Rampart at Gulfstream Park last month.

``She's an ultimate talent so we can't let her gallop alone,'' Desormeaux said about Rachel. ``I risked using my filly up but I didn't want to be second, I wanted to win so I truly feel like the mouse that got the cheese.''

Before the race, Unrivaled Belle appeared anxious. She broke away from the traditional post parade, galloped up the far turn by herself and arrived at the starting gate well before the others. She circled several times behind the gate while waiting to load.

Whatever pre-race jitters she had disappeared once the gate opened.

``My filly ran huge,'' Mott said. ``I don't think it was that the other mare (Rachel) ran poorly. She ran her race, too. We just outdid her.''

Rachel Alexandra broke sharply and got into a back-and-forth duel with Be Fair. Rachel took a brief lead heading into the backstretch and they continued to battle until Rachel regained the lead midway on the final turn.

But she immediately had company as Unrivaled Belle came up to challenge. Those two went head-to-head through the stretch, with Calvin Borel on the rail going to a left-handed whip on Rachel Alexandra. Borel had no comment afterward.

``I thought we were going to get beat again,'' Desormeaux said. ``I passed her in the lane then she got me at the eighth pole and I was like, 'Well, there's the class prevailing,' but Unrivaled Belle would not give in. She regained the advantage and would not return the favor.''