The 13/2 shot galloped clear of Irish Derby winner Trading Leather (9/2) and Hillstar (5/1) with 6/4 favourite Cirrus Des Aigles fourth.
Harbinger's 2010 record went by two seconds, with Novellist repeating his victory over star Cirrus Des Aigles at the Grand Prix de Saint-Cloud with Johnny Murtagh in the saddle for his fourth triumph in the race.
"It was a great performance but it didn't feel like we'd broken the track record by two seconds. I was always cruising and in my comfort zone," said Murtagh.
"I loved the way when I asked him to stretch he wanted to get on with it. He stretched well - pulling him up was probably the hardest part."
2011 Prix de l'Arc de Triomphe winner Danedream won the Group One King George VI and Queen Elizabeth Stakes last year.
Trainer Andreas Wohler was overjoyed after the win. Novellist has been beaten just twice in 10 starts.
"I can't describe it - it's dreamland," he said. "I used to come here as a kid and watch it as a kid in the school holidays and now I am here as a trainer.
"One of our strengths is we have horses who mature later and when stepped up in distance. I was confident as I knew he had improved since his last race but I didn't expect him to win by five lengths.
"It's the first time with the three-year-olds against the older horses and he has beaten the best three-year-olds easily.
"I was worried how confident Johnny was before the race because I thought he shouldn't be thinking it was so easy but he rode him as if he had ridden him 20 times before.
"The main race would be the Arc after this, and he will have a prep race in advance, either in the Prix Foy or more likely the Grosser Preis von Baden."
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- Horse Racing
- Johnny Murtagh
- Cirrus Des Aigles