Jockey Gavin Ryan was taken to hospital for precautionary checks after his fall led to the sixth race at Dundalk being declared void.
Having enjoyed a winner aboard 7-2 favourite Reverberation in the apprentice handicap earlier on the card, Ryan was partnering the Luke Comer-trained Guild in the Crowne Plaza Dundalk Race & Stay Handicap when his mount became short of room not long after the stalls opened.
Ryan was catapulted to the ground and was down for some time while being attended to by medics.
The rest of the field went on to complete almost a circuit before the race was called off before the home turn.
The stewards inevitably confirmed the race void, but Ryan thankfully appeared to escape with relatively minor injuries.
The Irish Horseracing Regulatory Board tweeted an update from on-course Dr Antonia Lehane, saying: "Gavin Ryan is fully conscious and talking. He is going to Drogheda Hospital for precautionary x-rays."
Short-head winner Reverberation was trained by James Lambe, who was full of praise for Ryan - who had a scare when unseated from the 7-2 favourite on the way back to the parade ring after the mile event, but was able to stay on his feet.
Lambe said: "It's great to get it. He was third here on his last visit and then I sent him to Newcastle and we were disappointed, but I think the straight mile is tough there.
"Going left-handed around two turns here suited. Gavin gave him a great ride."
Elsewhere on the card, Tony The Gent saw off his stablemate Yuften to land the Crowne Plaza Dundalk Race & Stay Claiming Race.
With a rating of 92, Yuften was favourite during the morning to claim an eighth course win, with his 75-rated stable companion Tony The Gent next in the betting.
By the time the pair entered the starting stalls, strong support saw Tony The Gent as the 10-11 favourite from 15-8, with Yuften drifting out to 6-4 from 8-11.
Given a positive ride from 7lb claimer Joey Sheridan, the seven-year-old Tony The Gent hit the front over a furlong from home and was two and a quarter lengths clear of his stable companion at the line.
"We'll take them any way they come, I thought it would be the other way around," said Hogan.
"This guy (Tony The Gent) has been running well here all winter and that's his ideal trip. The other fella just has a few issues and Joe (Doyle) felt he fell out of the gates, didn't travel great and then stayed on late.
"The winner has been good to us. It was James' (Macauley, owner of both horses) idea to claim him for 20,000 euro, I thought he was a shade dear, but to be fair the boys know what they are doing when they put in these claims. They have their homework done."
Juliet Rose was another winning favourite in the View Restaurant At Dundalk Stadium Maiden.
Ridden by Declan McDonogh, the Joseph O'Brien-trained 15-8 shot was always in control and had a length and a half in hand over Dutch Admiral passing the post.
"It was nice progression from her last run. She was unlucky the last day to just bump into one (second to China's Storm)," said McDonogh.
"Today was lovely, I had a grand tow along and she learned a good bit from the last day. Really it was never in doubt and she won nicely."