At 11-under-par, Parnevik leads Grant Waite by one. J.L. Lewis, Steve Lowery and Tommy Armour III are two back at 9-under.
With a field full of players seeking their first career PGA Tour victories, the top-five players through 36 holes already have at least one win under their belts.
Parnevik is a two-time winner in 2000, having claimed the Bob Hope Chrysler Classic and the GTE Byron Nelson Classic. Waite captured the 1990 Kemper Open. Armour also earned his first and only victory in 1990 at the Phoenix Open. Lowery won the '94 International; while Lewis entered the winner's circle at the 1999 John Deere Classic.
Friday, Parnevik made a bid for his third win of the season by carding one eagle, five birdies and just one bogey. However, the Swede's 65 was two shots higher than Lowery's round of 8-under-par 63. Armour matched Parnevik's 65 with the help of a pair of chip-in birdies at the 10th and 17th holes.
Doug Barron, who was one of three first-round co-leaders, is now in 6th place alone at 8-under after shooting a 2-under-par round of 69. Fellow overnight leader Jason Buha slipped six shots off the second-round lead after posting a 1-over-par 72.
Parnevik's Ryder Cup teammate, Sergio Garcia, is tied for 7th, four off the pace, after shooting a Friday 67.
Defending champion Mike Weir is still in the hunt. Canada's Native son is 6-under-par, following rounds of 67-69.