The queen, accompanied by her husband, Prince Philip, watched the race from a private box with friends. The royal couple appeared oblivious to the television cameras that provided occasional live shots.
Famous for her hats, Elizabeth wore a large-brimmed number in a light green that matched her coat. The crown was trimmed with a reddish-pink scarf.
Her majesty's weekend in Kentucky is a break in an otherwise official six-day trip that included a speech to the Virginia legislature and a stop at Jamestown to mark the 400th anniversary of English settlement in North America. On Monday, the queen and prince are scheduled to attend a state dinner at the White House, and on Tuesday they will reciprocate with a dinner at the British Embassy.
Elizabeth and Philip were staying at Lane's End Farm in Versailles, owned by Will Farish, a former U.S. ambassador to Britain.
"We didn't really do anything because I don't think they really wanted us to," Versailles Mayor Fred Siegelman told the Lexington Herald-Leader. "They just wanted it to be a real quiet and a private visit. That's what Secret Service is saying."