Ten-time champion trainer saddled eight winners across three cards on Saturday - at combined odds of 45,863/1.
Nicholls was responsible for five of the seven Ascot winners, plus two at Wincanton and one at Haydock, where he also had a neck second having sent just three runners up the M6.
With stable stars Cyrname and Clan Des Obeaux doing the business in the Ascot and Denman Chases respectively, some of the Ditcheat lesser lights also did their bit as the Nicholls team - according to the trainer himself - exceeded its own previous daily best.
Brio Conti, Worthy Farm and Silver Forever completed the job in Berkshire, to go with Wincanton wins for Grand Sancy and Magic Saint, plus Haydock glory for odds-on Quel Destin on an afternoon to remember for Nicholls.
He said: "We've had seven in one day before, but we've never had eight in a day. We've had five here, and it has been a brilliant day.
"We are always trying to do what is right for the horses and get the right results. Seeing what Cyrname did today, I would have to say was one of the performances of the season.
"If he had run against Altior here at the last meeting, it would have been really interesting. Today proved how good we thought he might be.
"The highlight of the day was Clan, who is going for the Gold Cup - and for him to go round and do that is just awesome."
Nicholls surprised by Conti
Brio Conti could make his next appearance at the top table after surviving a stewards' inquiry to kickstart the winning spree with 25/1 surprise in the Ascot Supports Berkshire Community Foundation Handicap Hurdle.
Nicholls said: "I knew the horses were really well and I knew they would run really well. It has been an amazing day."
The trainer admitted Brio Conti's win was unexpected, adding: "He has surprised me, because I thought he needed a run and he is still as big as a bull.
"He was just not ready the other day. It was heavy ground at Sandown, but I couldn't do any more with him at home. He has come on for that, and he will come on for that today. Where this leads, I don't know.
"I thought he would finish in the middle today, come down 5lb and run in the Coral Cup - but we could go for the Aintree Hurdle.
"We've always thought of him being good, but we have not been able to get there really."
Worthy Farm (5/1) proved half a length superior to his rivals in the Best Racing On Racing TV Handicap Hurdle, while Silver Forever (2/1 favourite) claimed the closing British EBF Mares' Standard Open National Hunt Flat Race.
