Cyrname won the Ascot Chase by 17 lengths after Cheltenham Gold Cup contender Clan Des Obeaux, both under Harry Cobden, landed the Denman Chase.
Brio Conti, Worthy Farm and Silver Forever were other winners in a five-timer at Ascot.
The 10-time champion Nicholls also had a Haydock winner and Wincanton double.
Nicholls said: "I knew the horses were really well and I knew they would run really well. It has been an amazing day."
Meanwhile, the 2015 Cheltenham Gold Cup winner Coneygree was retiredat the age of 12 after being pulled up at Ascot.
British racing was enjoying its first weekend of action after a six-day shutdown because of equine flu outbreaks.
Some trainers were unable to run their horses because of new vaccination rules, but Nicholls had stated that his team had not been affected.
Remember the name - Cyrname
Cyrname produced the day's most striking performance on a bumper nine-race card at Ascot.
Waiting Patiently, trained by Ruth Jefferson, was left trailing in second as Cyrname triumphed again after a 21-length win at the same track last month.
"I had no idea he would improve like he has done. It is an astonishing improvement," said the Somerset-based trainer.
The horse - who prefers jumping at right-handed tracks - is unlikely to go left at next month's Cheltenham Festival.
Nicholls indicated the Punchestown Gold Cup in April and the King George VI Chase at Kempton eight months later would be targets.
The trainer won his 10th King George in December 2018 with the fast-improving Clan Des Obeaux, and this victory confirmed the seven-year-old as a leading player in the Gold Cup on 15 March
Subscribe by Email
Follow Updates Articles from This Blog via Email
No Comments