Grant takes Scandinavian Mixed for second title on European golf tour
"Standing here, now as a winner again in my hometown. Amazing," Grant said.
Grant started the final round 11 shots behind her Swedish compatriot but shot a seven-under 65 while Soderberg struggled to 77.
The 24-year-old chipped in from the bank above the gree for her seventh birdie of the round at the 18th to beat Soderberg and Scot Calum Hill by one stroke.
Another Swedish woman Johanna Gustavsson was three shots further back in a tie for fourth with Englishmen Alex Fitzpatrick and Andy Sullivan.
Grant started fast, making four birdies in the first six holes. She made two more at the ninth and tenth.
"Honestly I just tried to go out today and give myself an opportunity. I didn't even think that I had the chance of winning," she said. "Eleven shots is a huge gap.
"So I just wanted to go out, have fun and make as many birdies as possible. And enjoy it with my brother on the bag and being at home.
"It turned out to be an incredible day."
