Frankie Dettori has teamed with trainer John Gosden to secure a treble on the opening day at Royal Ascot, highlighted by the victory of Without Parole in the St James's Palace Stakes.

Injury prevented Dettori riding at the meeting 12 months ago, but those memories were quickly banished with the 9-4 favourite stretching his unbeaten record to four when he lifted the Group One prize by half a length from Gustav Klimt.

Dettori, who picked up a seven-day whip ban for his efforts, which means he is set to miss the Coral-Eclipse at Sandown, was thrilled to be back.

"To have three winners in a week is amazing," Dettoir said. "To have three winners on the first day is fantastic."

Victory for Without Parole fulfilled a dream for winning owner John Gunther, who together with daughter Tanya was responsible for breeding this year's US Triple Crown winner Justify.

"This is the number one of anything I've ever done in my life," Gunther said.

"To actually breed a horse and get him to Royal Ascot in a Group One and to pull this off is something I've dreamt about my whole life.

"I don't think I can ever top the emotion of this day."

Gosden is a firm believer the best is yet to come from Without Parole, who is a son of the mighty Frankel.

"He is a grand horse," he said. "There were no hiding places in that race, it was a proper Group One pace. I think he is still on the up."

Calyx got the ball rolling for Gosden and Dettori in the Group Two Coventry Stakes and Monarchs Glen completed a memorable day at the office for the pair to claim the Listed Wolferton Stakes by a length.

"That was my 59th winner at Royal Ascot," Dettori said.

"I've got all week to get to 60. Let's hope I can do it."

Eve Johnson Houghton found her emotions getting the better of her when Accidental Agent became her first winner at the meeting with a 33-1 shock in the Queen Anne Stakes.

"I thought I was tilting at windmills and I dreamt about being third," she said.

"I thought 'my god, I'm going to be placed' - there was an awful lot of screaming going on."

In the King's Stand Stakes, Blue Point wore down Battaash to claim top honours for trainer Charlie Appleby and jockey William Buick.