Aidan O’Brien landed the Queen Mary Stakes for first time ever when True Love came home strongly to score at odds of 9/4.

Having chased home yesterday's Coventry Stakes winner Gstaad over six furlongs on her second start at Navan, True Love was sent off the 9/4 market leader to get Aidan O'Brien and Ryan Moore off to a flying start in the five-furlong Queen Mary Stakes.

Somewhat surprisingly, Aidan O'Brien had failed to land the Wednesday opener heading into the day two of Royal Ascot, and it looked like the same stat might remain at the halfway point, as Ryan Moore was hard at work on the daughter of No Nay Never whilst Karl Burke's impressive Nottingham debut winner Zelaina took the field along.

However, she soon found her stride and began to make significant headway towards the near side, keeping on to strike the front in the final furlong.

Charlie Clover's longshot Flowerhead, who was sent off a 100/1 following her success at Chepstow eleven days ago, set off in hot pursuit more towards the far side, but she never looked like getting on terms with Ryan Moore's mount and ultimately had the settle for second place.

The winning distance was a length and a quarter, with half a length back to the American raider Lennilu, who emerged with plenty of credit for trainer Patrick Biancone and jockey Luis Saez.

O'Brien, who has now won every juvenile race at Royal Ascot at least once, said: "True Love had two very good runs, finishing second to a good filly [Lady Imam] the first time and then our own colt beat her the second time.

"Ryan said he thought she would be better when she steps up to six furlongs. The only thing is that she was drawn by herself. There was no pace where she was, so she had to do her own work and that's what Ryan did. He was excellent on her. He wasn't going to wait on anybody. I think probably the strongest part of her was the last half a furlong – when she got going, she really powered away.

"She is a big, mature, strong filly; walking around the ring, she was like a four-year-old, and that's not making little of anything else. She is just so big, mature and scopey. She is something to look forward to."

Reflecting on her two defeats, O'Brien said: "She had her first run and Ryan came in and said, 'They won't beat her again'. Her second run, Wayne came in and said, 'They won't beat her again'. Then you see the two that beat her, so…!

"She is obviously high class. The lads will decide, but you would imagine she'll have no problem going six, although she is a No Nay Never and he is a big influence for speed."

It was a second success of the week for rider Ryan Moore, who added: "True Love is a tall, scopey girl. She looked a different class to the others down at the start.

"She is a No Nay Never and they're usually big, strong, powerful, fast two-year-olds; she's got all that size, but she feels like she'll be better suited when she goes a bit further.

"She was second first time in a Listed race, beaten by a smart filly, and then obviously the colt that beat her won yesterday, so the form was there."

The opening five-furlong contest was unfortunately marred by a sad incident which saw Richard Hannon's Harry's Girl suffer a fatal injury.