The Ditcheat handler began the afternoon on 97 winners for the campaign and sent a strong team of five runners across Somerset.
He was double-handed in the Broadway & Horton Cricket Club Novices' Hurdle, with punters unable to split stablemates Iliko D'Olivate and Pleasant Man, who were the 6/4 joint-favourites.
Pleasant Man ran with credit in defeat to finish third, but Iliko D'Olivate was an authoritative six-length winner under Harry Cobden, with Syd Hosie's Way Out best of the rest in second.
Nicholls and Cobden swiftly doubled up with Cap Du Mathan (6/4) in the Summerfield Developments Novices' Limited Handicap Chase before 2/5 shot Rare Middleton brought up the trainer's century with victory in the first division of the Invest Southwest Maiden Hurdle.
The latter won on the Flat at Leopardstown in October before changing hands for 215,000 guineas and looks an exciting addition to the hurdling ranks.
"He's a very smart horse and there's loads more to come from him," Nicholls told Racing TV.
"He only started schooling six weeks ago and I don't like running them that soon, but he'd been outside on the grass luckily enough twice and he's going to learn so much from jumping.
"I was concerned first time on this ground about whether he'd get the trip and everything else, but he's a nice horse and I'm sure we'll hear a lot more from him."
Nicholls did not have to wait long for winner 101, with Afadil comfortably justifying odds of 8-15 in division two.
The son of Camelot gave his supporters a fright by almost refusing at the first flight, but ultimately won comfortably by two lengths, seeing Paddy Power cut his Triumph Hurdle odds to 16-1 from 33-1.
"I'm very happy with everything - the way the horses are looking, the way they're running and the way Harry is riding. Everybody is working hard at home, it's fantastic," Nicholls added.
Cobden said: "I think they were all very well placed and it's nice when you've got some good, young stock coming through.
"All three of the novices are nice horses. The first one (Iliko D'Olivate) is going to want plenty of time, Rare Middleton is green but knows his job and jumps well and felt like a nice horse and so did the last one. He handled the ground well and apart from a little scare at the first, he jumped well and was very straightforward after that.
"When you're riding for someone like Paul Nicholls, the job is a lot easier because if something goes wrong you've got the next one to put it right.
"I'm sure it would be a lot harder riding for someone else who doesn't have the same strike-rate."