LIBERTARIAN will be aimed at the St Leger after finishing a hugely impressive second in Saturday's Investec Derby, with trainers Karl and Elaine Burke hoping to pick up a string of summer prizes en route to the Doncaster classic.

The long wait for a northern Derby winner goes on after Ruler Of The World secured Aidan O'Brien's fourth Derby victory on Epsom Downs, but Libertarian confirmed his status as one of the leading three-year-olds in the country as he flashed home to claim second spot.

The Dante winner stayed every yard of the mile-and-a-half trip, and the extra two furlongs of the St Leger will hold no fears for the Burkes, who train at Spigot Lodge between Middleham's High and Low Moors.

Libertarian is generally a 5-1 second favourite for the final classic of the season, but he is likely to have at least two more outings before lining up at Doncaster.

“We'll have to look at the other big races now,” said Karl Burke, who enjoyed the greatest day of his training career as Libertarian defied odds of 14-1 to finish second. “He's not in the Irish Derby, but we could supplement him if we wanted to. The track would suit him well.

“The King George is also an option, as is the St Leger. It would mean so much to us to win the Yorkshire classic.”

Libertarian looked like trailing in among the also-rans after a muddling early pace left him in the penultimate position as the Derby field turned around Tattenham Corner.

He was still in the back three places at the two furlong marker, and was no better than mid-division as the leaders entered the final furlong.

But a flourishing finish enabled him to edge ahead of Galileo Rock and Battle Of Marengo on the line, and he eventually finished just one-and-a-half lengths behind Ruler Of The World.

He couldn't have stayed any better, and jockey William Buick feels he might have won had the first half of the race not been run at such an inconsistent pace.

“The first thing William said as he got off was that the pace of the race did for him,” said Burke. “They went really slowly for the first part of the race and then they kept quickening it up and slowing it down until the field reached Tattenham Corner.

“We're delighted with him though and we know we've got a proper horse. He's lived up to all of our expectations and more.

“When we got him at the beginning of the year, we thought we had a nice, raw three-year-old who might be a staying type, but he keeps on getting better. He's come on so much in the past three months.”

Libertarian could face Ruler Of The World again in the both the Irish Derby and St Leger, although O'Brien is still to finalise the plans for his Derby champion.

It looked like Battle Of Marengo would win for Ballydoyle when he got the first run on the inside rail, but Ruler Of The World, ridden by Ryan Moore, was always in contention and never looked like being passed after he eased to the front heading into the final furlong.

“The two horses we thought had the best chances were Battle of Marengo and Ruler Of The World,” said O'Brien, who saddled five of the 12-horse field. “We thought the world of Mars and hoped Flying The Flag would step up, but they were the two we thought were top of the pecking order.

“We're just so lucky. We get these incredibly-bred horses and even before they are mated, the dream is for this to happen. It's incredible, we are very privileged to be in the position we are.”

Prior to the race, most of the talk had revolved around favourite Dawn Approach, but things could hardly have gone any more disastrously for the 2,000 Guineas winner, who eventually trailed in last.

Jockey Kevin Manning could not get Dawn Approach to settle in the early stages – the colt was throwing his head around violently as soon as the stalls opened – and had to send the favourite to the front at the halfway stage.

However, he never looked comfortable, and the writing was on the wall long before he was headed at the start of the home straight.

“There was no pace, and the horse did not settle,” said Dawn Approach's trainer, Jim Bolger. “There was nothing there when Kevin pulled him out.

“Dawn Approach had been running over a mile, where they were jumping out with a strong pace. Kevin just dropped his hands down his withers and let him bowl in those races. I doubt you will see him again at a mile-and-a-half.”