D.A. Points is alone in second place after a 4-under-par 66 on Thursday.
Paul Azinger, the 1993 PGA champion, carded a 3-under-par 67 in the opening round and is tied for third place with Tom Pernice, Jr.
Smith, whose only win on the PGA TOUR came at the 2002 Buick Classic, collected his first birdie of the round at the par-5 third. He elected to lay up with his second shot, but hit his third to 3 feet. Smith converted the short birdie putt, then parred his next three holes.
At the par-4 seventh, Smith missed the fairway with his drive, then landed his approach on the back fringe. He used a 5-wood to putt and drained the 50-footer to reach 2 under par.
Smith hit an 8-iron 25 feet short of the stick at the eighth, but he ran home the birdie putt. He capped off three birdies in a row when he holed another 25-footer at the ninth.
'Today I actually made some putts, which is always fun for me,' said Smith. 'It doesn't happen on a real regular basis, and my putter felt great. I made some long ones and everything just kind of happened.'
Smith parred his first six holes on the back nine, but broke back into red figures at the par-5 16th. He went for the green in two, but fell into a greenside bunker. Smith blasted out to 7 feet and drained the birdie putt to reach 5 under par for the championship.
At the par-4 17th, Smith was between clubs and pulled the 7-iron for his approach. His second went over the flagstick, but he sank the long birdie try to polish off his 64.
'The golf course is playing tough,' admitted Smith. 'I'm not sure what happened. Everything started clicking together and working. I was playing well and I kind of felt like that all year.'
The numbers don't reflect Smith's contention that he has been 'playing well all year.' He has made three cuts in eight starts this season on the PGA TOUR and his best finish was a tie for 42nd at the BellSouth Classic.
'It's hard to tell by how much money I've made this year, but I really played pretty well,' said Smith, who has only pocketed $39,020 this season for 207th on the money list.
Points did all of his damage on his opening nine, the back side at Southwind. He ran in a 4-foot birdie putt at the 10th, but lost the stroke at 12 when he could not get up and down from short of the green.
He birdied three holes in a row from the 13th and all were from 15-18 feet. Points holed a long birdie putt at the 17th, then parred his final 10 holes to reach minus-4.
'It's going to take a lot of patience and some real creativity to work the ball into the hole, landing it either well short of the pin or trying to float it into the wind and hope it lands pretty soft,' said Points.
Fred Funk, Mark Calcavecchia, Daisuke Maruyama, Paul Stankowski, Steve Stricker, Zach Johnson and three-time major champion Nick Price are knotted in fifth place at minus-2.
David Toms, the winner of this event in 2003 and 2004 and the runner-up last year, posted a 1-under-par 69 on Thursday and is part of a group tied for 12th place.
Defending champion Justin Leonard struggled to a 2-over-par 72 and is tied for 46th place.