For a while the Nicky Henderson-trained gelding was pushed hard by Sizing Europe, but eventually went on to win the Queen Mother Champion Chase by 19 lengths.
"He is an unbelievable horse. To beat Sizing Europe the way he did was a remarkable performance. He was keen early on but settled down. He's a class act. I think the 'Frankel of jump racing' is a fair way to describe him," Geraghty told BBC Sport.
The victory means that Sprinter Sacre has still not been defeated over fences.