The 4-year-old Munnings filly and 2-5 favorite stalked the pace of early leader Paid Up Subscriber, effortlessly moved by late in the final turn, and cruised to the wire under a hand ride by Florent Geroux to win by seven lengths.
The Larry Jones-trained filly completed the 1 1/8 miles in 1:49.98 to clinch her third grade I win, following the July 16 Delaware Handicap and the 2015 Cotillion Stakes.
"She ran really big. When it came time to run, she really exploded down the lane very nice," Jones said. "It seems like her numbers are getting better after every race, so I think she's at the peak right now. We hopefully have room for improvement."
Paid Up Subscriber held to finish second, followed by Genre and Engaginglee. Miss Pink Diva was pulled up by jockey Shaun Bridgmohan in the first turn with an apparent hind-leg injury and was euthanized, according to the Lexington Herald-Leader.
Paid Up Subscriber set fractions of :23.98, :48.30, and 1:12.57 through six furlongs but was no match for I'm a Chatterbox in the stretch. After a mile in 1:37.06, I'm a Chatterbox opened up a 3 1/2-length lead and extended her advantage to the wire.
"Today she broke very sharp, which allowed us to take a great position, where I wanted to be," Geroux said. "She was nice and relaxed. When I asked her to go down the lane, she gave me a very nice kick. I was like, ‘Wow. They're going to have to go fast to catch me.' "
I'm a Chatterbox now has an 8-3-2 record and more than $2.2 million in earnings from 16 starts. Up next, she'll head west to likely take on Songbird, Stellar Wind, and Beholder in the Breeders' Cup Distaff (gr. I).
"I think this may be the deepest Distaff that I have seen in a long time," Jones said. "There's seven really good horses. I'm putting her right there with them."