Simenon transferred his high-class flat form to hurdles when boxing on well to land the Kevin McManus Bookmaker Grimes Hurdle at Tipperary.
Willie Mullins' charge was second in the Gold Cup at Ascot in 2013 and fifth this year, but only had a record of two wins from eight starts over timber.
Darwins Fox made it as difficult as possible in the Grade Three, but Simenon (10-11 favourite) produced a slick leap when it mattered at the last and ran on well for Paul Townend to win by a length and a quarter.
Accepted showed a tremendous attitude to land the Listed Excelebration Tipperary Stakes.
Forced to run widest of all after the field made a beeline for the stands' rail, the 5-4 favourite was always prominent under Billy Lee and kept finding more in the closing stages to beat Simply A Star by half a length.
Colour Rhapsody ran on strongly to open her account at the second attempt in the Irish Stallion Farms EBF Maiden.
John Oxx's 7-4 favourite looked in trouble on the turn for home after being slowly away, but she picked up well for Declan McDonogh to beat Initial by three-quarters of a length.
McDonogh made it a double on the day when producing the Ado McGuinness-trained Oor Jock (11-2) with a tremendous late surge down the stands' rail to land the Follow Us On Twitter Handicap.
Johnny Lawman (7-4) showed distinct signs of greenness, but still had enough to get up to score in the Fillies Friday Night Out 8th August Maiden.
Forebear attempted to make all and was still in good shape a furlong out, but Fran Berry drove Johnny Lawman up and despite looking awkward at times, he had the momentum to land the spoils by half a length.
John Murphy's Kennedys Mor (25-1) landed the Costellos Tavern Handicap Hurdle under Tom Dowling.