Chantry House won the Marsh Novices' Chase as hot favourite Envoi Allen crashed out in the opening event on day three of the Cheltenham Festival.

Envoi Allen was sent off the 4-9 favourite to extend his unbeaten record to 12, but he got no further than the fourth fence, where he appeared to clip the top of the obstacle before crumpling on landing.

That left the Grade One heat wide open, and it was Nico de Boinville who seized the initiative aboard the Nicky Henderson-trained Chantry House (9-1).

Shan Blue made a bold bid for glory kicking on down the back in the two-and-a-half-mile contest, but he had no answer as Chantry House and fellow Henderson inmate Fusil Raffles swept by at the top of the straight.

The duo enjoyed a fine battle to the line, but Chantry House was just three lengths too good. Asterion Forlonge was third.

It was a 70th Cheltenham Festival winner for Henderson.

Envoi Allen, owned by Cheveley Park Stud, was moved from Gordon Elliott's Cullentra operation to Henry De Bromhead in the wake of photos of Elliott sitting on a dead horse emerging on social media.

Jack Kennedy is met by Henry de Bromhead after Envoi Allen's departure

Henry de Bromhead reported his charge to have emerged unscathed after his spill.

He said: "Jack just said he was a little bit keen. He just launched at the fence, unfortunately, and that was it.

"I've had a look at him though and he looked fine, and Jack's fine too, so that's good." 

As for the winner, Nicky Henderson told ITV Racing: "You have to take your opportunities when they're given to you, to be fair we all thought we were up against it when we started. I hope he's all right, Envoi, he looks OK.

"They both jumped beautifully, they still went a good gallop and we should be delighted. He's a wonderful horse, they both are.

"He's done nothing wrong all season, he really looked flat out a lot of the way. We said when we ran him in the Supreme last year that he wanted another half a mile and today he wanted another half. It really looks like we might be asking for three (miles) one day."

De Boinville added: "Third in the Supreme last year, all credit to the team at home for bringing him back. He slightly suffered in the soft ground round here in December, but I'm just absolutely delighted. I hope that Envoi Allen is all right.

"To be fair, I didn't even know he'd come down. I was wondering when he was going to come and pick me up in the straight, it's news to me when and where he went.

"Never discount Nicky Henderson round here, or ever. It's been a tough couple of months, but the horses seem to be returning to form and I trust in the guv'nor."