Champion race horse Think About It has been retired from the sport after miraculously surviving a horrific fall during Saturday’s $3 million Sydney Stakes at Randwick.

Think About It rounded the bend at the back of the field and appeared wobbly before collapsing in a heap on the home straight.

Jockey Jason Collett was thrown from the mount, but was able to walk away unharmed.

Know the news with the 7NEWS app: Download today

Owners confirmed on Sunday that the six-year-old, who won last year’s The Everest, has run in his last race.

Racing analyst John Walter said it was a relief to find out that the horse was OK, posting a distressing angle of the incident.

“Graphic footage (but) love to hear Think About It will be living life like a King from here on out in retirement,” he said on Sunday.

“But huge respect for Jason Collett in a crazy dangerous situation, trying to comfort the horse without any hesitation.”

Collett’s instinctive reaction was to try to help the horse back to its feet while it was laying on the turf in clear distress.

Despite everyone fearing the worst, Think About It was remarkably able to walk off the track.

“Think About It has walked off the track and into his box and had a good drink,” Bruce McAvaney later said on Saturday.

“We think he’s OK. That is quite remarkable, that’s the best news we’ve had, at this stage that’s a bit of a miracle.”

RacingNSW later said Think About It suffered a bleeding attack.

“Think About It, which collapsed in Race 6 due to a bleeding attack, has recovered and is under veterinary care. Jason Collett was uninjured in the incident and has been cleared to fulfil his remaining engagements,” they tweeted.

Collett was stunned the horse survived the fall.

“I’m OK and amazingly the horse has walked back to the stalls,” Collett said.

“They don’t do that. I thought he’d broken down but he’s bled out.”

Trainer Joe Pride provided another update later in the day.

“I walked down waiting to see the worst, and I saw his big head bobbing up above the screen. It was such relief. He’s a beautiful horse and we’ll take the best of care of him,” he told Channel 7.

“Just a big relief, it’s not often it ends that well.”

Think About It won The Everest last year and has amassed more then $12m in prize money.