Winner of a novice event at Stratford last week, Gary Moore's charge made a seamless switch to Grade Two level as he sprinted a length and three-quarters clear at the line.
Last year's winner Sanctuaire gave his rivals an early advantage after dwelling at the start and it was his fellow Paul Nicholls inmate Toubab who set the early gallop.
Barry Geraghty was always sitting on his heels aboard Finian's Rainbow though, biding his time to jump to the front at the third last.
However, Jamie Moore was just starting to get to work on Sire De Grugy and he moved up to challenge at the second-last, before edging ahead after the last and pulling clear in the shadow of the post.
Wishfull Thinking kept on for third, a further four and a half lengths adrift.
"Straight after he won at Stratford last week I was saying to everyone he'd run a big race here," said Jamie Moore.
"I just wish we'd got him to Aintree as he'd have given them something to think about in the Grade One.
"Dad has taken a lot of horses that aren't really top-class to all the big Festivals and every one ran above themselves.
"He really knows how to prepare a horse for the big day."
The winning trainer said: "I thought the track would beat him today with the stiff uphill finish as he's better on a flat track.
"That might be it for the moment, unless I can find a race in France which is always an option.
"It will make it dificult as I want to dodge Sprinter Sacre for as long as possible. The Desert Orchid at Kempton would be in the back of my mind for next season."
Geraghty was pleased enough with the runner up and said: "He ran a good race. In an ideal world they would have gone a better gallop as he was just tapped for toe but Jamie has given his a peach of a ride."
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