Na picked up his first PGA Tour win since 2011 after many close calls at the Greenbrier Classic this week.
Na was one shot behind co-leaders Kraft and Harold Varner to begin the day.
Both are seeking their first tour wins in their 85th starts.
No third-round leader has gone on to win the tournament since its debut in 2010. "I've been close so many times and failed so many times". Putting the work in, knowing I'm working as hard, if not harder, than I ever have.
"I never got ahead of myself".
Na shot a final-round 6-under 64, highlighted by five birdies on his first nine holes.More news: Section 377 Hearing in Supreme Court
Varner III fell away with a 72 to finish tied for fifth.
"I know I've come back from six shots a couple times in my career", Watson said. It was an easy putt, obviously, and all I needed to do was two-putt. "I'm getting better as the week goes on, and I'm building some momentum for my two-week stretch over in the United Kingdom, and I'm looking forward to getting over there". So it goes back to keeping it in perspective.
Varner sank a nine-foot birdie putt at 11.
Kraft, who finished fifth in last year's tournament, refused to get down on himself despite bogeys on two of his final three holes Saturday. "Playing from the fairways out here, you give yourself a good shot".
Fifteen golfers were within five shots of the lead. The 2016 tournament was canceled after devastating floods. "It's why I play golf - all the practice days, all the misses, all the bad moments, all are taken care of with putts like that Making two of them from nearly identical positions, I mean, that's a bit of a bonus".
Kraft had a one-stroke lead entering the round, the first time he's led after 36 holes on the PGA Tour.More news: Joaquin Phoenix's Joker Origin Movie Gets Greenlight! | Joaquin Phoenix, Movies, Todd Phillips
Kraft was rolling early, shooting even par through the first nine holes before bagging birdies on 10, 11 and 12 to stretch his lead.
Na said the win this week did more than just get the proverbial monkey off his back - it provides the 34-year-old a great confidence boost.
"Around the greens, on the greens, as firm as they were, as slick as they were, this was a U.S. Open-type of golf course today".
Defending champion Xander Schauffele and Kevin Na were at 13 under. He finished off a bogey-free final round to post a 22-under 266, two shots clear of Kyle Jones (69) and Sebastian Munoz, who birdied his last two holes to salvage a 70.
"Big confidence boost", Na said.
Snedeker recorded eight birdies and two bogeys on his climb up the leaderboard and was encouraged about his play 10 days before the beginning of the season's third major tournament, the Open Championship at Carnoustie in Scotland.More news: Zaman leads Pakistan to T20 tri-series title