Ryan Blaum and Andrew Putnam each shot 64 and were tied for second, and C.T. Pan (65) and Wesley Bryan (66) followed at 8 under.
"I feel my game is really good, really solid", said Pan, a former University of Washington star now in his second year on the Tour.
Johnson and Putnam were tied for the lead at 15 under after the third round and were five strokes clear of the rest of the field.
Cook's 5 under on Sunday tied him with Phil Mickelson and Tim Herron for the best scores of the final round and moved him up the leaderboard into a tie for sixth.
The win ensures Johnson will return to the top of the rankings as the golf world prepares for the second major of the season at next week's US Open at Shinnecock Hills, New York.
Dashcam captures officer rescuing wandering child from busy road
According to a Naperville police spokesman, the boy ran out of his mother's home when she wasn't looking. At one point, a large truck can be seen passing within a few feet of the child at a high rate of speed.
Johnson birdied the third hole and bogeyed the fifth to make the turn at even par. He wound up three-putting for double bogey. "I've got a lot of control of my golf ball and that's what you're looking for going into any week, but yeah, especially going into [Sunday] and then obviously next week".
"Just wanted to play, stay sharp", Johnson said.
"When you're around or in the lead you can definitely feel the pressure but I like it", Johnson, 33, said. "Normally you have to drive it really well to succeed here but my iron shots have been good when I've been in the fairway and I've managed myself out of the rough really well".
Langer closed the bogey-free round with a 12-foot birdie putt on the par-4 18th at Wakonda Club.
Young Girl Enters Rehab for Fortnite Addiction
A new entry in the popular Mario Party series, which blends video game and board game together, will be released on 5 October. Her parents also noticed payments totalling more than £50 a month were being paid to Microsoft from their credit card.
He previewed his dramatic finish on the par-5 16th.
Johnson holed out a sand wedge from 111 yards on the par-4 No. 1 for eagle and almost holed out again on No. 2 from 114 yards, tapping in from 9 inches for birdie.
Snedeker, who lives in Nashville, Tennessee, hadn't played this event three hours away from his home in five years and none of his eight PGA Tour victories have been at the TPC Southwind.
He holed out for eagle from 170 yards on the final hole to seal an emphatic six-stroke victory at the St. Jude Classic.
Real Madrid for Conte — Marca
Michel Salgado sees no reason why his former Real Madrid teammate, Guti , can't become the next Los Blancos boss. Guti called me to thank me for my interest". "I think for him it's good news he left Real Madrid ".