Tidal Bay (9/2) snatched victory in the final strides of the Lexus Chase at Leopardstown for Paul Nicholls and Ruby Walsh.
- Related Content
For the majority of the Grade One contest, the headline writers were preparing glowing tributes to Flemenstar as the favourite swung off the bit and jumped with his usual aplomb.
However, he began to tread water having jumped the last and Andrew Lynch soon sent out the distress signals.
First Lieutenant appeared to be the biggest danger as Sir Des Champs also rallied but Walsh produced Tidal Bay to challenge between horses just yards from the line to put his head in front on the post.
The eleven year old took up his customary position at the rear of the field as Midnight Chase, Hidden Cyclone and Quito De La Roque cut out the early running.
Midnight Chase kept on gamely despite losing his place at around halfway but he was always struggling in this company as was Pandorama who failed to threaten on his return from a lengthy absence.
Sir Des Champs' jumping was far from fluent and he made mistakes at the two fences on the far side, losing lengths and momentum at each obstacle.
In contrast, Flemenstar eased towards the head of affairs with Lynch at pains not to commit his charge too soon.
There was no such concern for China Rock who committed for home on the turn into the straight as Hidden Cyclone cried enough and China Rock was soon followed through by First Lieutenant.
It looked for all the world as though they were just playing for places, however, as Flemenstar appeared to be travelling all over his rivals but the needle on the petrol gauge swung to empty to set up the most dramatic of finishes.
The winning margin was a head with Hennessy Gold Cup third First Lieutenant in second, a half length and a short-head in front of Flemenstar and Sir Des Champs.
Winning owner Graham Wylie said: "This is up there with Inglis Drever. Back In Focus and now Tidal Bay. Both looked like they were beat over the last and both came with a great run in the end and just nicked it.
"I thought our fella was cooked four out, but then he started to come again. He's just got guts that horse.
"Paul has done an amazing job with him and Ruby as well. He gave him a great ride because you have to be patient. He's an odd, quirky character even at home but it was a great training performance and a great ride."
"He had the right man riding him, you wouldn't want to be in front too soon because you know he would pull himself up, so to have a bit of a scrap and come past them was ideal," said the British champion trainer.
"To get him back from where he was to do what he has done today is one of my proudest moments. I believed he'd go well today but you never know. He'd improved from Newbury and even though he's an 11-year-old he's just a high-class horse going forward.
"He's probably the best he's ever been. He'll have an entry for the Gold Cup and probably also have an entry for the World Hurdle.
"What he wouldn't want at Cheltenham is fast ground as that wouldn't help him over fences. We've got two nice options but on today's form if the ground was soft he's a big player in the Gold Cup."
Walsh admitted he would love to see Tidal Bay run in the World Hurdle in the absence of his injured stable companion Big Buck's, winner of the race for the last four seasons.
The jockey said: "I'm glad it was a test as it suited me. A hundred yards down I thought I was getting there. I'd love to ride him in the World Hurdle with no Big Buck's.
"He jumped the second-last well and I got through the gap going to the last. He was really finishing and I thought I had a chance of getting to them.
"He was a bit flat-footed at the last and he took time to pick up, but when he did he started to fly and I guess 100 yards down I was thinking I was going to get there.
"Everyone was in the same boat. We all knew Flemenstar's stamina had to be tested and Midnight Chase went a good honest gallop and the tempo was upped all the way. It was a real true-run contest.
"He's a different horse this year. He won at Wetherby, was second in the Hennessy at Newbury and has come and won today. It's brilliant."
Peter Casey said of Flemenstar: "Andrew (Lynch) said he pulled too hard. Maybe it would have been better if he had gone off in front.
"I don't think it was too far for him today. He boiled over a little bit. We had a job putting a saddle on him. He wasn't settled. Andrew said we'll have to go for the Hennessy and you have to do what the jockey says."
Mouse Morris was thrilled with the performance of First Lieutenant, saying: "I was delighted with that. He won't go to the Hennessy. He'll have a break and will go straight to Cheltenham for the Gold Cup."
Reacting to the result, Joseph Burke for Stan James in Ireland, said: "It was billed as Flemenstar versus Sir Des Champs, round two, but Tidal Bay stole the show under a terrific Ruby Walsh ride. We have slashed Tidal Bay's odds for the Cheltenham Gold Cup from 20-1 into 10-1 while Bobs Worth has shortened to 11-4 favourite (from 4-1).
"Tidal Bay had previously run a brilliant race in the Hennessy Gold Cup, when he was second, less than three and a half lengths away from Bobs Worth, and he was giving him 6lb that day, so that was some performance in retrospect.
"Last year, the Lexus proved to be the best trial for the Gold Cup with the hitherto unheralded Synchronised progressing to win at Cheltenham on his very next start so nobody should underestimate this result.
"Of last year's novices, Sir Des Champs probably emerged with the most credit and connections can be happy with him, given his season presumably revolves around the Gold Cup, for which he can now be backed at 8-1 (from 6-1)."
Sky Bet go 10/1 from 16s about Tidal Bay for the Cheltenham Gold Cup with his Hennessy conqueror Bobs Worth cut to 3s from 4/1.
Sir Des Champs was left unchanged at 6/1 for the race while Flemenstar (3/1 from 5/1) and First Lieutenant (6/1 from 8/1) were cut for the Ryanair Chase.