John Gosden’s Lucarno played to a full house of more than 30,000 at the redeveloped Doncaster yesterday and, persuaded to put his best foot forward, he gave Jimmy Fortune his first Classic success in decisive fashion in the £500,000 Ladbrokes St Leger.

Racing’s oldest and the season’s final Classic attracted 10 runners, four of them trained by Aidan O’Brien, and it was his Mahler, with Mick Kinane on board, who went to the front from the outset and was in front at the quarter-mile marker.

Kinane, however, reported that the colt had “changed his legs dramatically and lost momentum” at that point and having been headed by Lucarno approaching the final furlong, he rallied but was still a length adrift at the line.

Gosden, who trains the winner for a long-time patron of his stable, George Strawbridge, was saddling his second Leger winner having sent out Shantou to win the extended one-mile, six furlong test in 1996. “Lucarno was good enough to be fourth at Epsom in a very good derby behind Authorized and then he won the Voltigeur at York,” he said. “He was second in the hottest maiden all season on his debut this year. We will put him away now and he will be a lovely horse for next year.

“I should think he will go for the Coronation Cup [at Epsom] and then the King George at Ascot next season. It has been great race on a great day, I have never seen a crowd like this here. The atmosphere is out of this world.”

Strawbridge, 69, is based in Pennsylvania, but this was a race he was not keen to miss and his journey from America was rewarded in some style. He said: “I am so proud of this horse. People say the St Leger kills a horse as a stallion but I breed them to race.” O’Brien’s Honolulu started favourite and finished third, with jockey Johnny Murtagh reflecting: “They went too slow for the first six furlongs for me and when the winner quickened my fellow could not go with him.” Champion jockey Ryan Moore felt the pace wasn’t quick enough for Regal Flush, who was given a supplementary entry for the race at a cost of £40,000. He stayed on to finish fourth and recouped nearly £30,000 for his efforts.

One of the season’s big sprints, the Ladbrokes Portland handicap, provided a thrilling finish with Tim Etherington’s Fullanby just getting the better of Paradise Isle under a cracking ride from P J McDonald.

Etherington said: “The plan now is to go for the Ayr Gold Cup next week.” A 5lb penalty takes his weight to 9st 2lb.

McDonald, who has been concentrating on Flat race riding since winning the Scottish National at Ayr in the spring, said: “I am going to concentrate on the Flat this winter and give the jumping a miss. I have had a word with my boss, Ferdy Murphy, and he has said he will back me in whatever I want to do.”

The apprentice find of the season, William Buick, was found guilty of careless riding on Qadar and as he had already been suspended for a total of 24 days for similar offences in a rolling 12 months, he has been referred to the Horserace Racing Authority and could face a suspension of 14 days. Luke Morris was suspended for two days for a similar offence on Orpsie Boy.

Champion Moore was successful on Mark Johnston’s McCart-ney, who impressed in the Group 2 Urban-i, and Sir Michael Stoute’s Galactic Star in the Doncaster Audi Stakes. Arabian Gleam won the Group 2 GNER Stakes under Murtagh and trainer Jeremy Noseda said afterwards: “I should think that we will now have a look at the Prix de la Foret [at Longchamp] and the Challenge Stakes [at Newmarket].”

- Odds-on favourite Yeats gave Aidan O’Brien a precious first win in the Irish St Leger at the Curragh, edging out stable companion Scorpion.

The dual Ascot Gold Cup winner, ridden by Kieren Fallon and priced at 4-7 yesterday, wore Scorpion down to claim victory by half a length. Yeats remains the 10-1 second-favourite for the Melbourne Gold Cup behind 8-1 shot Purple Moon.