Hahn, playing on the Spyglass Hill course, birdied his final three holes to end at 12-under 202, catching up with second-round leader Snedeker.
The latter golfer, playing at the Pebble Beach course, carded his second straight 68.
Meanwhile on the Shore Course at Monterey Peninsula Country Club, Chris Kirk registered a 6-under 64 to claim sole possession of third place at minus-11.
One shot further back at 10-under 204 was Patrick Reed, who posted a 67 at Monterey.
Richard H. Lee, playing at Pebble Beach, fired a 66 to finish 54 holes in fifth place at minus-9.