McIlroy finds going tough as Lee cuts into Koepka's lead

Rory McIlroy failed to muster a birdie in a two-over front nine at the US PGA Championship as Danny Lee threatened to challenge Brooks Koepka’s place at the top of the leaderboard.

Koepka set a challenging target in the clubhouse with a stunning opening round of 63, the defending champion’s blemish-free effort leaving him clear at seven under.

The American’s performance overshadowed playing partner Tiger Woods, who ended up signing for a two-over 72.

Out later in the day, McIlroy’s hopes of making an impact in the opening round were hampered when he bogeyed his first hole.

The 2014 champion also dropped another shot at the eighth to reach the turn in 37, leaving him languishing down in a tie for 60th.

In contrast, New Zealander Lee surged through to five under after 14 holes before a bogey at the 15th saw him slip three shots behind Koepka.

Dustin Johnson and Jordan Spieth were at level par after 10 holes, the latter suffering a double-bogey six at the taxing 10th to spoil what had been a solid round up to that stage.