Shane Lowry cards 66 at Open Championship as Rory McIlroy struggles

Ireland's Shane Lowry plays out from a bunker on Hole 16 during the first round of the Open Championship in Troon, Scotland. (Maja Smiejkowska/Reuters)

Shane Lowry made the ideal start to his bid for a second Open title as Rory McIlroy effectively wrote off his chances of doing the same at Royal Troon in Scotland.