The well-supported 11/8 favourite September provided Aidan O'Brien with his fifth victory of the week at Royal Ascot and 60th winner of the Royal Meeting with a smooth success in the Listed Chesham Stakes.
Ridden by Ryan Moore, registering his sixth win this week, the two-year-old daughter of Deep Impact was settled towards the rear of the field early on as Mark Johnston's Nyaleti set a stern gallop in front in the seven-furlong event.
However, O'Brien's charge kept on powerfully in the closing stages and displayed a potent turn of foot to score by two and a quarter-lengths with the long-time leader Nyaleti (10/1) battling on resolutely to finish second.
The master of Ballydoyle won this event with subsequent English and Irish 2000 Guineas winner Churchill last season and September was trimmed into 5/1 from 14/1 for the fillies' equivalent at Newmarket next year.
Coolmore were also registering their fifth success of the week and are now one behind Godolphin in the race for the Royal Ascot Leading Owners' Award.
O'Brien said: "You would have to be delighted with her - she learned plenty today. She is out of Peeping Fawn and by Deep Impact, so she is bred absolutely in the purple. She has a massive engine, a great traveller and quickens really well.
"Seamus [Heffernan, jockey] loved her when he rode her at Leopardstown [won by five and a half-lengths]. She was very impressive that day and what's unusual about her is not a very big filly but she thinks she is big - she has a big personality. Like those very good ones, she has a real presence about her.
"She could be anything. Seamus was really happy with her at Leopardstown and Joseph said that she was the first two-year-old we had win first time out this year. Ryan saw her and wanted her for this race. It's very exciting.
"You would imagine that she would stay much further in time. We might try and finish the season racing at a mile and then see where we go next year - I'm delighted that she does have the pace to run at seven.
"She could go to the Debutante and then onto the Moyglare next. She is bred to stay very well, so we were thinking of running her in the Albany Stakes, but Ryan [Moore, jockey] thought we should come to this race."
September gave Ryan Moore, the leading jockey at Royal Ascot this week, his sixth winner.
It was also back to back wins in the race for connections after Churchill's victory last year.
"She's was always happy in the race, she travelled very comfortably," reported Moore of the 11/8 favourite. "Mark's [Johnston] horse went out there made it real test, has gone a good gallop and has kept going. September's run a very good race.
"She's only had her first race a couple of weeks ago, she's done a lot very quickly. She's done everything right, she's very straightforward. She is a little doll of a thing, but she travelled like the winner throughout the race.
"I never really had to get into her - and it was a good target for her to run down. She did it very nicely.
"Her mother kept getting better with racing as she got older and this filly has definitely got some of her talent. She is by Deep Impact and he won up to a mile and six, the dam was exceptional, so you couldn't ask for a better pedigree. You would say that, as she goes further, she will get better."
September is by leading Japanese stallion Deep Impact and out of Peeping Fawn, the winner of three Group One races and runner-up in the G1 Epsom Oaks.
September holds an entry in the seven-furlong G1 Moyglare Stud Stakes to be run at the Curragh in September.
The Mark Johnston-trained filly Nyaleti, ridden by John Egan, went down by two and a quarter lengths to the Aidan O'Brien-trained favourite September after a bold front-running show in the seven-furlong Chesham Stakes.
The two-year-old came to Royal Ascot off the back of a debut win at Salisbury six days earlier.
Johnston said: "We ran her last Sunday, we knew she was fairly good - we were staggered when she drifted so much at Salisbury because we hadn't gone all the way to Salisbury expecting to come nowhere.
"We went there principally also to win the Tattersalls bonus as she was one of the cheapest horses in the Book One sale last year and we were determined to win a bonus with her. So we got that last Sunday and it was too late then to enter her in anything other than the Chesham here - she should have been in the Albany.
"So we've gone a furlong too far today. We had suspicions that that was the case before we ran her, but she's done not bad after a furlong too far. She'll probably go to the Cherry Hinton next. It's the obvious race for her. She's clearly got lots of natural speed and lots of natural ability."
Egan was thrilled with the feeling he had on the roan daughter of Arch: "Mark thought she would run really well and she did nothing wrong. With a trainer like Mark she could go on anywhere. I knew Ryan [Moore] was on a very good one so I was always thinking he was going to come, but I stayed on well for second and I'm very happy with the run. I think she'll improve again."
Trainer Charlie Appleby was happy with third-placed Masar in the Chesham Stakes but indicated the horse will be given time to strengthen up before returning later in the campaign.
The New Approach colt won a six-furlong maiden at Goodwood on his only previous start before stepping up for this Listed assignment.
Appleby said: "The winner is obviously a very smart filly but I'm pleased with our fellow - I thought he looked very well beforehand.
"He is a horse for the future. I'll give him a bit of a break now before bringing him back in late summer, early autumn when we'll step him up to a mile.
"He'll appreciate going further but he'll need to furnish a bit more."
Fourth-placed Bartholomeu Dias was third to Masar in that Goodwood maiden and again finished behind that rival, this time by three and a half lengths.
Trainer Charlie Hills said: "I think our horse has improved. A furlong further and he could have been second. He's going to stay well."
