The seven-year-old cruised to a 19-length success over Sizing Europe, twice a Festival winner, in the two-mile contest.
His stamp of authority drew comparisons with Frankel, who retired unbeaten last year after winning 14 flat races and is the highest-rated horse in the modern era.
"He's a class act. I think the 'Frankel of jump racing' is a fair way to describe him," Irishman Geraghty told reporters.
The 1/4 favourite became the shortest-priced Festival winner since Arkle won his third Gold Cup at odds of 1-10 in 1966.
"It was like Barry Geraghty pressed the accelerator on a sports car. It was one of the most wonderful things I have seen in sport," said winning trainer Nicky Henderson.
"It does make you speechless. Sprinter Sacre is scary. He has that aura about him and is totally and utterly unique.
"He finds it ridiculously easy - he just loves doing it."