Australian Aaron Baddeley moved up two places and carded his second successive 66 to take a one-point lead at the half-way point of the Barracuda
Baddeley, 37, hit six birdies and did not drop a shot at the Montreux Golf and Country club, with his round giving him an overall score of 26.
First-round leader Ollie Schniederjans is a point behind following a costly bogey on the third and an even more costly double-bogey on the par-3 seventh.
Three Americans – John Merrick, Andrew Putnam and Sam Saunders – are tied for third on 23 points, three behind the leader.
The Barracuda Championship – formerly known as the Reno-Tahoe Open – uses a Modified Stableford format, which allocates points based on the number of strokes taken at each hole.
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Eight points are awarded for an albatross, five for an eagle, two for a birdie, zero for a par, minus one for a bogey and minus three for a double bogey or worse.
Ireland’s Shane Lowry moved up five places to tied-sixth with a round of 67, while compatriot Seamus Power is in a six-way tie for 13th.
Martin Laird dropped eight places to tied-19th on 17 points, while Graeme McDowell just made the cut on seven points.
Watch the third round of the WGC-Bridgestone Invitational from 7pm on Saturday, live on Sky Sports Golf.