Hot favourite Untapable thrilled a crowd of more than 113,000 when she pulled well clear of My Miss Sophia to win the $1 million Kentucky Oaks by 4.5 lengths at Churchill Downs on Friday.

The Steve Asmussen-trained filly by Tapit covered the 1 1/8 miles in 1:48.68, just .04 of a second off the stakes record set in 2003 by Bird Town.

It was the second Oaks win for owners Winchell Thoroughbreds and Asmussen after their 2005 success with Summerly.

"It feels great," said winning owner Ron Winchell. "We were here with Summerly in 2005. It's very important to us; owning the sire and the mare being a part of the family for so long."

"She's just a great filly," said Asmussen, whose stable has been the focus of recent allegations of horse abuse.

Untapable was ridden by Rosie Napravnik, who won her second Oaks in the past three years. She was aboard 2012 winner Believe You Can.

"She was really great," Napravnik said of Untapable. "She got into a great stride and relaxed. She is magnificent.

"I wasn't worried about the post (13) like some people were. She has grown up and she is maturing.

"I am so thankful for Steve and for the Winchells having me on the filly. They have done such a great job.

“She is moving forward all the time and she was perfect today."

The race was delayed as Empress of Midway flipped in the gate and was on the ground inside the gate for some time.

Jockey Corey Nakatani had to be pulled out of the starting gate before Empire Of Midway was scratched from the race and taken back to the paddock.

All the fillies were taken out of the gate and jockeys were off their horses. It took several minutes for the riders to be remounted and reloaded into the gate.

At that point Fashion Plate was unruly in the gate, but the field was sent on its way with jockey Gary Stevens with his feet out of the irons.

The Santa Anita Oaks winner broke in the air and trailed the field. Kiss Moon was also hampered at the start.

Despite all the drama Untapable broke well from the outside post and settled fourth as Sugar

Untapable was three to four wide but leaving the final turn it was down to My Miss Sophia and the favourite, but that changed quickly in the stretch as the winner asserted her class.

Untapable was the even-money favorite for a reason. In her two starts this year prior to the Oaks she won the G3 Rachel Alexandra Stakes at Fair Grounds by 9 1/2 lengths and the G2 Fair Grounds Oaks by 7 3/4 lengths.

Last season she won two of four starts including the G2 Pocahontas Stakes at Churchill Downs.

The Oaks win was worth $576,600 bringing her career earnings to $1,124,725 with a 5-0-1 mark from seven starts.