Dustin Johnson lays down gauntlet with six-under 66 in Sawgrass first round

• ‘Obviously if I play really well I’ll still be No 1’, he says
• Justin Rose has a 68, Jordan Spieth balloons to 75Dustin Johnson has no apparent intention of giving up his position at the top of the world rankings lightly.Justin Rose, Jon Rahm, Jordan Spieth and Justin Thomas arrived at the Players Championship in the knowledge they could knock Johnson from the ledge upon which he has sat for 15 months by Sunday evening. Johnson’s response, typically, arrived