Quick Suzy provided trainer Gavin Cromwell and jockey Gary Carroll with their first Royal Ascot success in the Queen Mary Stakes on Wednesday.

Carroll delivered Quick Suzy from off the pace on the stands side to challenge favourite and eventual runner-up Twilight Gleaming a furlong out, stretching clear to win by a length and a quarter at 8/1 – with 50/1 outsider Cheerupsleepyjean almost another two lengths back in third.

Co Meath trainer Cromwell is more often associated with success over jumps – including at Grade 1 level at the Cheltenham Festival – but is adept on the flat, too.

Quick Suzy, a maiden winner at the Curragh last month and then a Group 3 runner-up at Naas, has nonetheless broken new ground for the yard with her Group 2 victory.

Cromwell said: “Royal Ascot is such an occasion and to have a winner, it's fantastic.

“I was very confident Quick Suzy was going to run a big race, but where she lay with the English or the American horses, we didn't know until we came here.

“She won her maiden well, it was only an auction maiden and it wouldn't carry as much weight, but she then went to a G2 in Naas [Coolmore Stud Irish EBF Fillies Sprint Stakes] and finished second. She showed blistering pace and we thought plenty of her.

“I'm not a known as a trainer of two-year-olds or sprinters, so it was very hard to tell but I knew she was in great nick. This goes down to the staff at home and the big effort they have put in.

“The plan was she would remain with me until Royal Ascot and then go to America. Maybe we can twist the owners’ arm and go for the Breeders’ Cup with her.”

Carroll said: “Fair play to Gavin, three-mile Stayers’ Hurdle to five furlongs at Ascot - he can do it. She was very good today.

“She didn't have the best prep, but to be fair he got her here spot on today. She travelled well, travelled very easy - I thought we didn’t go quick enough. I knew she’d get to the line well today and would probably outstay the American horse.

“She jumped well and I thought the American horse would be going a really good gallop and that I’d be chasing, but I actually sat close to the American horse and every step of the way I was waiting, waiting, and then when I got inside the two, the American horse got maybe half a length on me and I chased her down. I just outbattled her to the line, and we actually got to the line well. She’s a very good filly.

He added: “This means a lot - the season’s going very well so far, but you need these big winners really to put yourself on the platform, so it’s great to get it. Especially today, with the crowds - it’s a long time since we’ve felt an atmosphere like that, and it was magical.

“If I could have extended the walkway back in, I would have - I soaked it all up and it was great. It hasn’t really sunk in yet, but it was a magic race to win, with such prestige; it’s what jockeys dream of.”