Simenon gave leading National Hunt trainer Willie Mullins his first taste of Royal Ascot success when careering away with the Ascot Stakes in the hands of Ryan Moore.
Mullins is a regular trainer of winners at the Cheltenham, Aintree and Punchestown Festivals, but is a rare visitor to the summer showpiece meeting.
A high-class Flat performer for Andrew Balding before joining Mullins to go hurdling, Simenon showed some smart form in his first few appearances over timber.
The 8-1 chance travelled powerfully throughout the two-and-a-half-mile contest and showed a nice turn of foot in the home straight to win by six lengths.
Al Khawaneej grabbed the runner-up spot, with outsiders Nafaath and Scots Gaelic filling the places.
Mullins said: "I've never been here (winner's enclosure) before, we've lost in a few photos finishes.
"I thought the omens were good when Danny Shum had a winner here earlier (Little Bridge) from Hong Kong because he used to work for my father back in 1978 I think.
"This horse has just improved. Hurdles have made him settle, they've been a big help.
"I said to Ryan to settle him on the rails and if you can't ride your own race. I hoped they'd gone fast enough and they weren't going to sprint away from him. Once he got him out and got running, he was gone.
"I think I might leave him here because he's in the Queen Alexandra on Saturday and we'll see how he comes out of this.
"I haven't any plans over hurdles. We brought him for Cheltenham, I thought he might win but he finished last so I thought it might have been the travel but the lad who does him said he settled much better and drank a lot of water which is a big thing."
