Scheffler shares US PGA lead as McIlroy struggles Image source, Getty Images Image caption, World number one Scottie Scheffler is looking to defend the US PGA Championship after winning at Quail Hollow last year By BBC Sport golf reporter PGA Championship first-round leaderboard -3 Kaymer (Ger), Scheffler (US), Smalley (US), Potgieter (SA), Jaeger (Ger), Lee (Aus), Hisatsune (Jpn); -2 Conners (Can), Reed (US), Lowry (Ire), Brown (Eng), Theegala (US), Greyserman (US), Schauffele (US) Selected others: -1 Thomas (US); Day (Aus), Smith (Aus), Rahm (Spa), Spieth (US); E MacIntyre (Sco), Fitzpatrick (Eng), Rose (Eng); +2 Fleetwood (Eng); +4 McIlroy (NI) Full leaderboard Going into this week's US PGA Championship, there was a fascination with how Aronimink would play and what challenge it would present. There was a strong feeling the Pennsylvania course might be ripe for being tamed. Instead of having its belly tickled and rolling over, Aronimink bit back on day one of the season's second major. It bit back hard.…