Echavarria birdies final hole to win PGA Tour's Zozo Championship
The birdie four enabled Echavarria to avoid a playoff with two-time major winner Justin Thomas and his fellow American Max Greyserman, who finished tied for second at 19-under par.
The Colombian reached the green in two at the par-five 18th and calmly rolled up a 40-foot eagle attempt to three feet before stroking home the winning putt at Narashino Country Club.
"It's surreal, this moment is very special," said the 30-year-old, whose previous win came at the Puerto Rico Open in March 2023.
"It's been a good year for me, I just haven't had that top result. I've been very consistent, I've learned a lot this year."
Echavarria took a two-shot lead into the final round where he carded a three-under 67 to finish on 20-under 260.
A bogey at the eighth and another at 14 had opened the door for Thomas and Greyserman but the Colombian held his nerve to birdie two of the final three holes for the victory.
"I don't think I would have won this week without the victory in Puerto Rico," he said.
"I pulled a lot of that moment in the last round on Sunday in Puerto Rico, I used it a lot this week to stay patient, stay calm.
"This is a very challenging course, there's a lot of hard holes and I was able to use that in my favour and I was able to get it done and beat two amazing players."
Thomas 'bummed'
Thomas, who had been looking to end a more than two-year title drought since his second major win at the 2022 US PGA Championship, also birdied 18 for a four-under 66.
"It's a mixture of obviously bummed and disappointed, but I played so well," said Thomas.
"I played plenty well enough to win the tournament. Hit so many good putts today that just didn't go in, that's the difference.
"I needed some of those ones that burned the edge to fall."
Greyserman had four birdies on the front nine and another on the 14th, but his birdie attempt on 18 to force a playoff rolled agonisingly wide of the hole as he finished with a 65.
"Didn't quite execute down the stretch when I needed to," said Greyserman.
"Nico stepped up there and he hit a great second shot. He earned it."
American Rickie Fowler was alone in fourth, three shots behind Echavarria, after a final-round 64.
Xander Schauffele, the winner of two majors this year, finished in a tie for 41st after a disappointing week.
He carded a quadruple bogey on the first day in a three-over 73 and though he bounced back with a 65 on Friday, he was never in the hunt and finished with a 69 and a five-under total of 275, 15 strokes adrift of the winner.
Defending champion Collin Morikawa finished tied 54th at three-under par.