Result:1 War Emblem (B Baffert) V Espinoza, 2 Proud Citizen, 3 Perfect Drift. 20 ran.

Outsider War Emblem gave trainer Bob Baffert his third Kentucky Derby victory with a bold front-running triumph on Saturday.

War Emblem, sent off at just over 20-1, defeated the D. Wayne Lukas-trained Proud Citizen by four lengths.

Perfect Drift was another three-quarters of a length back in third with Medaglia D'Oro fourth in the 18-runner field.

Neither Saarland nor Harlan's Holiday, the lukewarm co-favourites at 6-1, were a factor in the mile and two furlongs race.

 Photo Gallery: See this race in pictures

War Emblem's owner, Prince Ahmed Bin Salman, bought the colt last month and turned him over to Baffert, who immediately found himself with a Derby horse.

"We sort of came in here through the back door but we're leaving through the front door," Baffert said.

Winning jockey Victor Espinoza said his first Derby victory came easily.

"At the eighth pole I knew I had much the better horse than everybody behind me," he said.

"He was going so easy. I knew nobody was going to catch me."

War Emblem made virtually all the running and won with plenty in hand.

But Johannesburg, last year's top juvenile and one of two runners for Irish trainer Aidan O' Brien, never got in a blow.