The 23-year-old from Sarpsborg defeated England's Laura Davies after she holed a 35 foot uphill putt for eagle at the 459-yard par-five 18th hole in regulation play.
The pair shared the day two lead and carded matching final rounds of 69 to finish on 12-under-par 204 at Golf Club Le Rovedine.
Despite an early final round charge from Davies, Skarpnord caught the 72-time champion over the back nine.
Skarpnord went to the turn in 39 and was six strokes behind Davies with nine holes to play. She overcame the deficit with four birdies and an eagle for an inward total of 30 strokes.
She explained how her boyfriend, who is also her caddie, helped her to produce some of the best golf of her life.
"I played good on the back nine every day. Petter said when we turned at the ninth and I was three over he said, "Okay the back nine is your host; we can play great there." I like the holes and I did," she said.
Davies, who was four clear of the field after four holes in the final round and two ahead with one to go, could only manage a par at the 18th in regulation play after her second shot found the bunker short of the green and she missed the birdie putt.
Any attempts to avenge her playoff defeat to Swede Linda Wessberg in Austria five weeks ago failed as she missed putts to win at each of the three extra holes.
Her best chance came at the second time of asking when she faced an eagle putt from six feet that tricked past the hole.
"I played great today. I hit one bad shot. I hit a bad 8-iron on number six and had a double bogey. After that I played great again," said Davies. "That eagle putt in the playoff could have won it. It's a cruel
loss to be honest with you. It's very disappointing. The whole year has been very disappointing to be honest with you but what can you do."
Despite playing her second shot into the short greenside bunker three times in the playoff, Skarpnord was able to secure her second title, following her win at May's Deutsche Bank Ladies Swiss Open.
"It means a lot. I've been struggling for the last four weeks that I've been in the States. This was a big relief for me," she added.
With her prize winnings of €30,000, Skarpnord moved up to fourth place on the Henderson Money List, just behind Becky Brewerton, which should ensure a tense battle over the next two tournaments in China and Korea.
Skarpnord was also handed a week's holiday for two to Mauritius on account of her win, which she added will allow her to escape from her snow covered home in Norway this winter.
Topics: On Other Tours