Aidan O'Brien and Johnny Murtagh warmed up for Frozen Fire's assault on the Ladbrokes St Leger as Honolulu provided the duo with a second consecutive success in the National Express Doncaster Cup on Town Moor.
The trainer-jockey combination have tomorrow's Classic in their sights, with the Irish Derby winner set to start favourite, and were again the toast of punters as Honolulu scored as the 15-8 market leader.
Royal And Regal took no prisoners in the stayers' test when bowling along in front from the outset.
However, O'Brien's Queen Alexandra winner has bundles of stamina and put it to good use by pegging back Royal And Regal and staying on to collect by four lengths.
Balkan Knight came through to pip the front-runner for second, with half a length separating the pair.
Murtagh said: "He's a lovely horse and won well.
"He's been working well, has improved and Aidan has been delighted with him."
David Elsworth said of the runner-up: "We would have won without the winner, and I am very happy to pick up a good prize for coming second."
Royal And Regal's trainer Michael Jarvis added: "He just didn't quite get home and at this stage of his career I think two miles is probably his maximum trip.
"We'll now consider trying to win the Jockey Club Cup at Newmarket again."
Last year's May Hill winner Spacious returned to the Leger meeting in a bid to regain winning ways - but the 1000 Guineas runner-up made hard work of seeing off three rivals in the Frank Whittle Partnership Conditions Stakes.
James Fanshawe's 8-11 favourite required maximum assistance from Robert Winston to assert in the final half furlong.
Spacious also survived a stewards' inquiry into possible interference before being called the nose winner.
Fanshawe said: "She has been off a long time, the race turned into a three-furlong sprint and Robert said the ground would be slow enough for her.
"Although she is still in the Prix de l'Opera, the Sun Chariot has always been the aim and she has such a big physique that she should grow into it and be something to look forward to next year."
Kevin Ryan saddled his second Group winner of the year as soft-ground-loving Madame Trop Vite found conditions ideal in the Polypipe Flying Childers Stakes.
Ted Durcan's mount turned in an improved display last time out at Newbury and the 11-1 chance raised her game to squeeze through along the rail and deny fellow Yorkshire contender Anglezarke by a neck.
Ryan said: "She deserves this as we have always thought she was a high-class filly, but the ground is key to her.
"On this kind of ground she acts very well and I think she would get another furlong in it too.
"The Cheveley Park would be on her agenda, but the ground will determine where she goes."
A step up to a mile and three-quarters coupled with a softer surface unlocked improvement from The Betchworth Kid, who travelled sweetly in the Ladbrokes Mallard Handicap en route to a three-length success.
Trainer Michael Bell said of the 10-1 winner: "This was his big target after winning at Nottingham last time, and he is obviously a progressive stayer."
Bell blamed "trainer error" for not entering the three-year-old in the totesport Cesarewitch, for which the runner-up Bollin Felix was cut to 20-1 by the sponsors and Stan James.
Kite Wood, sent off 7-4 favourite, earned a quote of 20-1 with Ladbrokes for the Derby after landing division one of the EBF inspirepac Maiden Stakes, with Richard Hannon's The Miniver Rose (16-1) taking division two.
Paul Cole saddled his first winner of the meeting as Dream In Waiting (16-1) struck in the EBF Carrie Red Fillies' Nursery, with Elsworth getting on the scoreboard as 7-1 chance Closertobelieving held on in a nail-biting finish to the Free £30 Bet At harino.com Classified Stakes.