Long known as the race that horses like Hill Gail, Swaps, Affirmed and Sunday Silence won en route to Kentucky Derby glory, the Santa Anita Derby made history well before any of the aforementioned legends took their place as mainstays in the California racing timeline.

Like the San Antonio and Santa Anita Handicaps, the Santa Anita Derby came to be in 1935, making it one of the original races that has been at Santa Anita from the beginning. Its history with the Triple Crown really started in 1952 when Hill Gail became the first horse to sweep both that race and the Kentucky Derby. Of course, he was just the first of many champions who have gone on to glory in Louisville.

But a significant edition of the Santa Anita Derby happened thirteen years before Hill Gail became one of its victors. You will not find it as a part of Triple Crown lore, but the winner of that renewal accomplished something very special that day.

And as history will show in the present, it is something quite rare.

Fourteen horses comprised the field for the fifth Santa Anita Derby on February 22, 1939. As far as the public was concerned, the expected winner was Porter's Mite, who was bet down to 9-5. Outside of the coupled entry of Alfred Vanderbilt's Hysterical and Impound at 4-1, everyone else was seen as competing for the minor awards.

When the action got underway, Xalapa Clown assumed the role of pacesetter, and stayed in that position for much of the race. As for the principals, Hysterical was closest of all for the first half-mile. Only a couple lengths in back of Xalapa Clown, Hysterical did not spot as many lengths as either Impound, who was well off the pace. As for Porter's Mite, he was a few lengths back, but made up ground as he traveled along the Santa Anita oval. He was already well in contention with a few furlongs still to be run.

But Porter's Mite was not the only horse moving up. A filly named Ciencia, who had been several lengths down early on, had improved her position as the Santa Anita Derby progressed. Well into the second half of the race, she found herself in third, with only Xalapa Clown and Porter's Mite ahead of her. Then, in a matter of seconds, only Xalapa Clown was ahead of her. Porter's Mite was relegated to third (he would finish fourth at the wire). The crowd at Santa Anita were witnessing an upset, no matter who won.

Impound, who had been way back earlier on, moved up as well. He got by Porter's Mite late in the race as well, but third is where he would end up. Hysterical lost multiple positions, settling into seventh when all was said and done. Xalapa Clown led most of the race, but not when it counted the most.

After a mile and one-eighth around the Santa Anita course, Ciencia defeated her rivals handily to win one of the biggest races of the meet. And on that day, she made track history by turning into the first filly to win the great race. In a contest that has come to be assoicated with some of racing's immortals, Ciencia crafted a story all her own in the early days of the Santa Anita Derby. She made history before Swaps or Affirmed or Sunday Silence came around.

Just how special is that win? Well, it is special for a couple of reasons. First, the Santa Anita Derby is a prestigious race. And it is one of the staples of the track's annual schedule. Just given how its stature has grown over time, to be part of that list of winners is simply amazing.

The other reason is because Ciencia did something unprecedented. No filly won the Santa Anita Derby before her, so that automatically makes her a unique figure in the race's storied history. But well into the twenty-first century, it can be said that Ciencia is part of an exclusive group.

Since 1939, only two other fillies have claimed the title of Santa Anita Derby champion: Silver Spoon in 1959, and Winning Colors in 1988.

Not only have all three of them won the prestigious race, they have formed a prestigious club thanks to their respective victories.

But Ciencia, the filly campaigned by noted owner King Ranch and trained by W.J. (Buddy) Hirsch, is the one who started it all. And she can deservedly be called the head of that select gathering.