Midday, ridden by Tom Queally, became the first filly to win the Nassau Stakes three times after powering to victory at Goodwood.
The favourite travelled strongly throughout the 10-furlong Group One and produced a tremendous finish to lead entering the final furlong.
Snow Fairy provided the main threat to Midday, but the six-time Group One winner was too strong.
In the other feature, Chubby Chandler's Hoof It won the Steward's Cup.
But the victory for Midday caps a fruitful week at Goodwood for trainer Sir Henry Cecil, who also trains Sussex Stakes winner Frankel.
"It's been a wonderful week. All being well she'll go for the Yorkshire Oaks," said Cecil.
"She's been unlucky not to win more than six Group one races. She's a marvellous horse."
Hoof It, trained by Mick Easterby and ridden by Kieren Fallon, held off the challenge of Tax Free and Mac's Power to win in impressive style despite carrying the top weight.
Carrying a 6lb penalty following success at York a week ago, the joint-favourite was forced to concede weight to each of his rivals.
But having been covered up in the middle of the pack early, Fallon guided the winner to a convincing victory.
"He's done nothing but improve. Mick walked the course this morning and he told me to go to the far side so it made my job easier," said Fallon.
"I think he will be a Group One horse," he added.
The winner is jointly-owned by golfer Lee Westwood and his agent Chandler, who was thrilled with the victory.
"We will see what's what and we would like to have a go at all sorts of races," said a beaming Chandler.