Unquestionable runs out an impressive winner to lead home Aidan O'Brien 1-2 in Juvenile Turf

Aidan O'Brien and Ryan Moore have become the irresistible force in the Breeders' Cup Juvenile Turf and earned their sixth success in the event thanks to Unquestionable on Friday.

Racing in the colours of Al Shaqab Racing, he was due to be ridden by Frankie Dettori, but he was replaced by Moore when O'Brien's first string River Tiber was scratched.

A son of Wootton Bassett owned in partnership with the Coolmore partners, the winner landed a Curragh maiden in May before a second and fourth in the Railway and Phoenix Stakes.

He produced a fine effort last month at Longchamp in the Group 1 Prix Jean-Luc Lagardere when second to Rosallion and went one better, beating stablemate Mountain Bear and My Boy Prince.

Wrote, George Vancouver, Hit It A Bomb, Mendelssohn and Victoria Road were the previous Juvenile Turf aces for O'Brien, who said: "I'm delighted for everyone. River Tiber was withdrawn and I was gutted for the owners, while Dylan's [McMonagle] horse Mountain Bear ran a stormer.

"It's very tough to win here, but I'm delighted for the lads as they put so much into it. It's hard to explain because when things start bad [River Tiber missing out], it usually goes down because there are a lot of areas you can't control.

"Sometimes things fall for you and sometimes they don't but Ryan gave him a beautiful ride."

O'Brien, who has swept all before him in Europe, was winning a 17th Breeders' Cup race, which is some going considering D Wayne Lukas - a doyen of American racing - holds the record with 20.

Moore was recording a 13th victory at the meeting and said: "I had a bit of speed underneath me and was able to get to the rail, while I was happy at every stage. He's a Wootton Bassett and we thought a lot of him and River Tiber [also by the sire], but this fella ran well in the Lagardere. If things worked out better that day, I think he could have won. The winner is a really nice horse, but my lad has done that nicely.

"Aidan knows the right type to bring to this race and I'm delighted he and the second ran so well. I'm sorry for Frankie missing the ride but things fell for me."

Jerry Bailey, one of the greatest US jockeys, heaped praise on Moore when analysing his ride on the host broadcaster - something Coolmore partner Michael Tabor would no doubt agree with.

"This doesn't get old," he said. "It's great to enjoy it and a great moment because it's tough to have a winner here and River Tiber was taken out, but Aidan was still confident with this horse.

"River Tiber was our number one for sure, but there wasn't much between them. We then thought Unquestionable could win."

Mountain Bear, a Listed Dundalk winner, was taken to an onsite equine hospital and was reported to have suffered a fracture from which he is expected to make a full recovery.

Fierceness (John Velazquez) wins the JuvenileCredit: Edward Whitaker

Fierceness on fire in Juvenile

Fierceness advertised his claims for Classic glory next year when romping to victory in the Breeders' Cup Juvenile.

He was giving Todd Pletcher a fourth win in the race, while it was a second for jockey John Velazquez after Uncle Mo - one of the trainer's victors in 2010.

He ran in the same distinctive silks as the owner of Fierceness, Mike Repole, but never lived up to his promise.

By streaking clear of Muth and stablemate Locked, Fierceness laid bare what talent he possesses.

Repole said: "The horse worked so well the entire year. He had one bad race in the Champagne Stakes and most people - other than me and Todd - might have waited for another spot, but this horse is out of Nonna Bella, who is named after my grandmother, so it's really special.

"Johnny won on a two-year-old champion in Uncle Mo 13 years ago and I'm glad we won it for him."

Velazquez was also purring, adding: "He worked so well one morning. I didn't know who he was at the time, but he worked incredibly. He's small, but has a big heart."

Read these next:

'I cannot understand this' - owner dismayed as leading European hopes scratched from Breeders' Cup

Big Evs strikes in Juvenile Turf Sprint to provide Mick Appleby with Breeders' Cup glory

Hard To Justify denies Porta Fortuna to give Chad Brown a record-extending sixth Juvenile Fillies Turf winner