A look at the key hole Thursday in the first round of the PGA Championship:

HOLE: 18.

YARDAGE: 548.

PAR: 5.

STROKE AVERAGE: 4.571

RANK: 18.

KEY FACT: Jimmy Walker had a two-putt birdie from 40 feet at the turn to take the lead for the first time and keep it the rest of the day with a 65. Five players made eagle. Dustin Johnson made a bogey in his round of 77, and Phil Mickelson took four shots to reach the green in making bogey on his way to a 71.