Georges St-Pierre was an absolute mess the night before his fight with Nick Diaz, according to GSP's longtime Brazilian jiu-jitsu coach.

John Danaher, the right hand man of Renzo Gracie at his gym in New York, wrote Sunday on Instagram that GSP was puking all night prior to that bout with Diaz at UFC 158 in 2013. St-Pierre did eventually beat Diaz by unanimous decision in Montreal.

"Georges drank some watermelon juice for rehydration that had been too long out of the fridge and got a badly upset stomach," Danaher wrote. "He spent the entire night vomiting. It was so sad to see such a perfect camp get ruined at the last minute by such a minor oversight. The night of the fight, Mr St-Pierre came in underweight and drained. We had to curtail the warm up for fear of exhausting him before the bout even began."

Before then, Danaher described GSP's preparation as "probably the most flawless and well run fight camp." But you know that old saying about the best laid plans. (Danaher added that St-Pierre's camp for Carlos Condit was "probably the worst.")

"Yet despite our best intentions, there is always a good chance of things going awry that require spontaneous change and adaption in the face of unexpected circumstances," Danaher wrote. "All the major MMA fight camps I have been a part of furnished unforeseen incidents and drama that could not have been predicted and which had to be overcome."

Danaher said before the fight there was an issue with Diaz's camp wanting to double check the hand wraps. St-Pierre had to "put an on act of confidence and vigor" when Diaz's team entered the locker room, according to Danaher. The actual fight was not an act — simply another situation underscoring why St-Pierre was and is one of the greatest of all time.

"Mr St-Pierre showed why he was a great champion that night, putting on a dominant shut-out performance to win a unanimous decision - no one in the audience would have guessed how serious a problem he had to overcome," Danaher wrote. "He used a system of pacing the rounds and timing the takedowns and allowing standing escapes to maintain the pace of the fight whilst controlling the action but at the same time, not exhausting himself. It worked brilliantly and the problem was overcome."

St-Pierre, 34, has been talking comeback quite often lately after vacating his UFC welterweight title in 2013 and going on sabbatical. GSP battled through a torn ACL during that time off and seems to be targeting a return soon.