Tony McCoy’s new association with Denman came to a premature end as the pair parted company at the third-last fence in the Aon Chase at Newbury.
After putting in a practically perfect round to five out under his intended Cheltenham Gold Cup rider, Paul Nicholls’ runner clattered the fourth-last and was lucky not to unship McCoy.
However, he met the next fence all wrong again and McCoy could not hold on this time and crashed out of the plate.
That allowed stablemate Tricky Trickster to just edge out Niche Market in a thrilling finish.
Denman had been prominent throughout and looked to have built up a good rapport with his new partner as the 2008 Gold Cup hero put in a few of his trademark spectacular leaps.
The pair pulled clear turning into the straight but Niche Market was trying his best and making up a little ground coming down to the fourth-last.
Denman hit that one hard and as McCoy tried to regain his momentum, the third-last just seemed to come too quickly and the 10-year-old barely picked up at all, giving the 14-times champion no chance of keeping the partnership intact.
Tricky Trickster found a second wind for Ruby Walsh and flew up the straight to peg back Niche Market.
The latter did his best but had no reply with Tricky Trickster prevailing by a short head at odds of 8-1.
Bookmaker reaction was swift, with Victor Chandler cutting Tricky Trickster to 12-1 favourite for the Grand National. Niche Market is 14s from 20s for Aintree.
The same firm cut Kauto Star to 4-5 from 5-4 for the Gold Cup, while pushing out Denman to 3-1 from 2-1. Tricky Trickster is 25s from 50s.
Nicholls reported Denman to be none the worse for his spill straight after the race.
“It’s a job to see (what happened) from here,” he said. “The main thing is that he’s 100% OK. He’s not in distress and there’s not a mark on him.
“He just made a mistake and then another – but we’ll get him back, we’ve been there before.
“That is racing. He was travelling well until he made the mistake and I am obviously delighted to win the race with the other horse as winning races is what we are here for.
“What happened to Denman is a blow to everyone but they have off days, the ground was sticky and I’ll have a look at the replay and see if there was a reason for it.
“By no means can you write him off and we have five weeks to get him back.
“He has being going great at home so it will be back to the drawing board and Cheltenham is another day.
“Whatever decision you make it is OK if it goes right, but if it goes wrong people will knife you in the back.
“The owners wanted AP to ride him. Sam isn’t in the team this year so they could have the best jockey available.
“If Sam was on the team this year then he would have probably ridden him.
“We have five weeks off and don’t write him off – it is as simple as that.”
McCoy said: “I’m disappointed with him. I was really disappointed after the cross fence when I saw Niche Market was so close.
“I squeezed him off the bend towards the fourth-last but I just never felt him lengthen. I just never really felt I could get into him.
“I thought he would pick up more towards the fourth-last but I just didn’t get the acceleration I thought I’d get. Then he went to the third-last and stood off a mile and that was my lot.
“It’s one of those things. I’m disappointed for Paul Nicholls, Harry Findlay and Paul Barber because they let me ride him when a lot of people think I shouldn’t be riding him. Hopefully I will get another chance in the Gold Cup, we will see.
“I’ve had enough disappointments in racing to not let it bother me. All you can do is try to go out and do your best next time.”
Walsh admitted Denman’s departure had caught him unawares.
“I’m a bit shocked really,” he said. “I didn’t think AP (McCoy) looked overly happy with him throughout.
“My fellow has beaten the Irish National winner in Niche Market and I loved the way he jumped.
“He jumped super and really stuck his head down when I asked him to.”
Nicholls added of the winner: “It’s amazing how he got knocked at Fontwell on his return over hurdles but I told everyone he’d come on for the run.
“Once Denman had gone he stayed on and picked up. His next run will be the Gold Cup.”