Sweden's Noren saw off challenges from a charging Kazuma Kobori and Nicolai Hojgaard - Rasmus's Danish twin brother - to end a seven-year wait for his 11th European tour title.
Noren finished at 16-under following a final round of 67, sinking three consecutive birdies before then recovering for a bogey at the 18th on the back of a wayward tee-shot, to claim a first victory since the 2018 Open de France.
New Zealander Kobori had put himself into the clubhouse lead on the back of a superb seven-under 65, with four birdies and an eagle over the closing six holes.
Nicolai Hojgaard carded a five-under 67, with a bogey five at the 16th proving costly.
"It means a lot," Noren, who also won the British Masters in 2016, said.
"It was a great weekend. I don't think I have played like this for a very long time.
"There was a little hiccup on the last, but I am extremely proud of myself - to win a title for the first time in seven years, it feels great."
Japan's Keita Nakajima finished two shots back in fourth place, also with a five-under final round having dropped a shot on the last.
Overnight leader Matt Fitzpatrick carded five bogeys to end his round at two-over, fading into a tie for sixth at 10 under alongside fellow Englishman Marco Penge, who was level par for the day.
Rasmus Hojgaard, meanwhile, made sure of his spot in the European Ryder Cup team at Bethpage, New York with a closing round of 71 to finish on eight under for a share of 13th place.
The Dane knew he needed to secure at least a two-way tie for 29th or better to overtake Shane Lowry in sixth spot.
"I have been so stressed out on the course today," admitted Hojgaard, who had made bogeys on the 10th and 12th before sinking a birdie on the long 15th.
Leading Australian was Jason Scrivener, whose final-round 68 enabled him to share 24th place at six under, while Elvis Smylie ended with a 69 to finish at four under, tied for 33rd.
