Brandt Jobe, who had 34 points after three rounds and led by nine points, struggled to minus-three points in the final round to fall into second place with 31.
After Thursday's play was completely washed out, the first and second rounds were pushed back one day and the final 36 holes were played on Sunday.
The International uses the modified Stableford scoring system in which players are awarded eight points for double-eagles, five for eagles and two for birdies. They lose one point for bogeys and three points for double-bogeys or worse.
Goosen, who played the back nine first in the third round, went off the front side in the final round Sunday. He opened with a birdie on the first at Castle Pines Golf Club to move to 27 points.
'I got off to a very good start this morning starting on the 10th,' said Goosen. 'I birdied two of the first three holes and then played pretty solid and then made very bad bogeys on Nos. 17, 18 and 1. That really put my momentum down a bit, but I played okay after that. Then started off well again this afternoon.'
The two-time U.S. Open champion picked up two more points with a birdie on the third. Goosen lost one point with a bogey on the seventh.
Goosen came right back with birdies on eight and nine to jump to 32 points. Around the turn, he struggled to a bogey on No. 10.
The 36-year-old faltered to the third bogey of his final round on the par-4 13th to drop back to 30 points. Goosen parred his next three holes before birdieing the 17th to get to 32 points. That would prove to be the winning putt as he parred the last and Jobe was unable to catch him.
'Obviously when you win a tournament, you put four good rounds together, and I haven't been doing that this year,' said Goosen, who earned $900,000 for the win. 'I would have three good rounds with a bad round in between.
'I think I putted quite nicely this week, and that sort of is the key. I worked quite hard on my putting in the last two months to get that to where I was striking the ball well, so it saved me a few strokes this week.'
Jobe ended his third round with three straight birdies to enter the final round with a nine-point lead. He opened with a birdie on the first to move to 36 points.
The 40-year-old bogeyed the second. Jobe picked up on No. 4 after hitting his bunker shot well over a green and under a tree. The pick up meant he dropped three points on the hole and that dropped him to 32 points.
Jobe slid to 30 points after bogeys on seven and eight. He cruised around the turn with five straight pars.
The Oklahoma-native dropped another shot on the 14th to give back another point. Jobe birdied the 17th to get within one of Goosen. Jobe needed a birdie at the last to win, but he could only manage a par to end alone in second place.
'It's a great week. I did play some good golf,' Jobe said. 'Unfortunately I played nine terrible holes this afternoon.'
Jobe is playing this season on a major medical exemption after missing plenty of time over the past two years due to a hand injury.
'In 2003, I shattered what's called the hook of the hamate,' said Jobe. 'I had surgery in 2003 and was out most of the year. I started in 2004 and playing at my fourth tournament, I shattered it again, and went back to the same doctor. It's never happened. I was like some freak of nature because surgery is supposed to take away the bone. There's not supposed to be anything there.
'The second one was worse because when he went in there I guess it had some artery problems and a bunch of things, and I lost the feeling in my hand. But it took a good seven or eight months until I was feeling pretty healthy, and that's kind of when I started up this year.'
Rod Pampling, the 2004 champion, collected 12 points over the last two rounds, to move into a share of sixth place with 24 points. He was joined there by Tim Clark, Tim Petrovic and Joey Snyder III. Scott McCarron and former Masters champion Phil Mickelson were one point further back with 23.