The 40-year-old man, who was airlifted to hospital, managed to walk to the Coast Guard helicopter and climb on-board despite his ordeal.
Friends and family had remained at Downpatrick Head overnight on Saturday and they embraced each other when news of the successful rescue filtered through about 3.40pm yesterday.
The man, who is understood to be an experienced caver and who lives locally, was described last night as being in a "remarkably good condition considering his ordeal".
Michael Hurst, of Ballyglass Coast Guard, explained that the man had been pushed into the cave by a “freak wave”.
“He was with a female partner, and from what we know they were kayaking in the area and decided on low water to walk around the cliffs.
"He is an experienced cave rescuer himself, he knows the area and the conditions. They just got caught in a freak wave.
"There were kayakers who managed to grab her but unfortunately, he was pushed into the cave and was unable to come out.”
Darren Carey, officer in charge of Killala Coast Guard, said the man was "extremely lucky to survive how he did".
"His training stood to him,” said Mr Carey. "Once we figured out he was in that cave, we were able to get eyes on him fairly quickly.
"He was only able to communicate with movement. Now and again, he would move his hand or his foot.
"It would have been extremely difficult to hear anything with the sound of the waves and sea crashing around him.
"RNLI played a blinder. They stayed in contact with him every half an hour by shining a torch at him and shouting through a loudspeaker. He would salute back at them, which was very reassuring.
"Quite often, these things can go the other way, so we are so delighted this rescue worked out," he added.
Many of the rescuers had not slept in over 30 hours, forgoing breaks amid a determined effort to retrieve the man before darkness fell yesterday evening.
It is understood that while weather conditions hampered the rescue operation, the warmer temperatures over the last 24 hours may have saved the man from developing severe hypothermia.
"He was very lucky that the weather in September was this warm. Even the night before, it dropped down to 4C.
"He had gear on him (a wetsuit, a helmet and boots) which together with his experience went a long way to saving him," Mr Carey said.Michael Durkan, deputy officer commanding at Killala Coast Guard, explained the complex nature of the rescue carried out by the Irish Cave Rescue Organisation.
"The Irish Cave Rescue were fabulous. They were the ones who finally got into him.
"They had to put a line down the face of the cliff and thread a line down the roof of the cave. This meant they had to drill into the rock every metre and put in wall bolts with hangers. That took a long time.
"They then fed the line through and suspended themselves along the roof of the cave, and that's how they managed to get to him.
"Along the bottom of the cave, there is water and waves and surf, so it was just too difficult to navigate along the bottom.
"The cave is 40 metres deep, but it was a blind cave that tapered off narrower, so the further you went inside, the more difficult it became. He was only visible when the boat was at a certain height in the waves.
"It's not possible to look straight into these caves. There are jagged rocks on both sides. You had to be at a certain height to see him.
"Visibility was quite poor in there. You have no light and only have what's coming in from the mouth.
"It would be too dangerous to get a boat in. You would get smashed off the rocks.
"We were waiting for a lull in the weather. Several attempts were made by the boat yesterday and today, but it was just too dangerous.
"The lads would have been slightly over him, suspended along the roof when they managed to reach him. He was in good condition considering and was able to talk to the lads who got him out.”