Leishman's round of 64 at the Firestone Country Club consisted of eight birdies and two bogeys and he leads by one over Justin Rose, Charl Schwartzel and Ryan Moore.
Steven Bowditch and former winner, Adam Scott, are well enough placed at 1 under and in a share of 14th position while Matt Jones is at even par and John Senden and Jason Day at 4 over.
In Reno, Geoff Ogilvy has finally shown a form reversal with an impressive opening round in the modified stableford event at the Montreux Golf and Country Club modified stableford event. Ogilvy with 16 points in his opening round shares second with New Zealand left hander Tim Wilkinson.
The Australasian pair are two points behind Nick Watney and three points clear of Chad Campbell and Martin Laird.