Zach Johnson holds a one shot lead after one round of the British Open golf tournament, firing a 5 under par 66 on Thursday at Muirfield in Scotland. Colnditions were sunny but windy. Johnson leads two players by one shot including Mark O'Meara. Among others Dustin Johnson shot 68, three back and Tiger Woods and Phil Mickelson are both in with 69s. Rory McIlroy struggled to an 8 over par 79.