It was the second PGA Tour title of the year for the 2007 Masters champion, who celebrated his ninth career win with hugs from his children on the 18th green before heading off to board a charter plane put on by the tournament sponsor to fly him to Britain for next week's Open.
"It just feels awesome, I can't really put it into words," said Johnson, who is on the board of the directors for the John Deere tournament.
"This tournament has meant so much to me and my family over the years.
"I don't know if you can rank any of them (titles). They're all so ultimately special.
"Augusta is Augusta, you really can't push anything past that but I am really going to enjoy this one because this is supremely special."
The play-off began looking as if it was a tournament neither man wanted to win with Johnson's drive on the first play-off hole finding the fairway bunker. Matteson could do no better landing deep in the trees.
Attempting to punch out, Matteson watched his second shot skid across the fairway into the water where he was soon joined by Johnson both eventually carding messy double-bogeys.
Back on the 18th tee, Johnson found the same fairway bunker but this time produced a brilliant second shot that rolled within two feet of the pin leaving him a routine putt for birdie and the win.
Matteson with a two-under 69 and Johnson with a bogey-free 65 finished regulation at 20-under par 264 after a rollercoaster final round.
American Scott Piercy also returned an error free 65 to finish alone in third with 18-under 266.
Johnson began the day four shots behind Matteson, who had topped the leaderboard since firing a course record equalling opening round of 10-under 61.
Matteson saw his lead trimmed to a single stroke several times over the final round but fought off all challengers until he double-bogeyed the 15th and Johnson drained birdies at 13 and 14 to replace him atop the leaderboard.
Another birdie at 17 gave Johnson a two-shot cushion stepping onto the 18th tee but Matteson was not ready to surrender.
With victory fading, Matteson cancelled out his double-bogey in dramatic fashion rolling in a 60-foot putt for eagle at the par five 17th, the ball ringing the cup before falling into the hole to regain a share of the lead.
"I'm kind of shocked I got into a playoff because I just didn't play my best today but kind of hung in there," said Matteson. "Luckily that putt went in on 17.
"All in all, you go into a playoff and lose to a shot like that, I mean, that's an unbelievable shot.
"My hat's off to Zach. He drove it in the bunker twice and figured out a way to win."
Three-time defending champion Steve Stricker had been well positioned to make a late charge for a fourth consecutive crown but watched his chances disappear with back-to-back bogeys at 14 and 15 to fall four shots off the pace with three to play.
Stricker hit back with a birdie at 16 but was quickly in trouble again with a bogey at the 17th to finish with a one-under 70 and a tie for fifth.
Young Tom Morris, Walter Hagan, Gene Sarazen and Tiger Woods are the only male players who have won a tournament in four consecutive years.
"It was different. It was weird," said Stricker. "Wasn't that I wasn't focused and into it, I just didn't feel that like something good was going to happen.
"Maybe I was trying too hard. I don't know really what it was. I was trying to win the golf tournament. I wasn't worried about four in a row, I was just trying to win."
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