Katie Walsh gained a dramatic first success at Sandown as Conas Taoi ran out a fortunate winner in the Coldunell Amateur Riders' Handicap Chase.
Looking booked for second on the progressive Paul Morgan-trained runner, Walsh was gifted the three-mile race after Tom David, aboard likely-looking winner Silvergrove, fell out of the side door on the run-in after slipping out of his stirrups.
The incident left the 7-4 favourite to coast home 16 lengths clear of runner-up Quinz and post a fifth win from his last six starts.
Walsh said: "It is the first time I've been here.
"It's a great course and it was a great experience. The horse had a nice weight on his back and he gave me a great spin. It was great to ride over the Railway fences and the Pond fence.
"He needed the gallop as strong as it was. Despite what happened at the last I always felt he was getting there as he doesn't do much.
"If the shoe was on the other foot, though, and I was on the floor I would have said we would have held on. I think my fellow today has won with a bit in hand."
Following the race Ben Pauling, trainer of Silvergrove, who was making his debut for the yard, confirmed both horse and rider were fine.
He said: "What happened was that the strap that holds the stirrups to the saddle broke, leaving the stirrups nothing to hold them still. Both horse and rider are fine.
"Tom said he felt it go at the Pond fence and he would have probably gone earlier but for the horse being such a good jumper.
"Since we've had him his schooling has not been far off exceptional. It's just a shame as not many horses jump round Sandown like that.
"I was devastated for the owners as it would have been great to see them have a very good start."