The New Zealander, whose last success was in Indonesia a year ago, came in with a 67 to finish on 272, 16 under par, to pick up a cheque for pounds 91,660.
Victory was all the sweeter for Nobilo who believes the Volvo European Tour is getting tougher each year and that Nick Faldo's remarks about "comfort zones" were out of order.
"The cuts are getting lower and the standards are getting higher," Nobilo said. "After the way this year has gone I am delighted to win again. Five shots are difficult to get back."
Sandelin and Ireland's Raymond Burns, who finished joint seventh, proved that the tour is in a healthy state. Both stepped up from the Challenge Tour last season and are beginning to challenge the established order.
Nobilo showed signs of form and fitness at the US Open where he had a top 10 finish after recovering from the whiplash injury he suffered when he took his daughter ice skating.
He drew level with Sandelin, the overnight leader who shot a course record 63 on Saturday, at the turn thanks to an eagle at the first and five birdies.
Nobilo then made headway down the home stretch, although he was hardly comforted by the knowledge that Langer is always a dangerous competitor and never more so than on his home territory.
But a 73 on the opening day when he was suffering from a neck injury proved to be the German's downfall. However, he has never finished worse than second in his last three tournaments and has strengthened his position at the top of the Order of Merit.
The consolation for Sandelin was another big cheque as well a possibility of a Ryder Cup place just a year after stepping up the ladder. He moves into 17th place and believes another two good events could see him facing the Americans in September.
Scores, Order of Merit, Sporting Digest, page 25Reuse content