Seven days after Rasmus landed his third victory on the circuit in the Omega European Masters in Switzerland, Nicolai finished with a birdie at Marco Simone Golf & Country Club in Rome to claim his maiden success.
The Danish 20-year-olds are the first brothers to win back-to-back events on the European Tour, with Nicolai pulling off the feat after being the last player into the field at the 2023 Ryder Cup venue.
"It means a lot,” he admitted after signing off with a 71 for a 13-under-par 271 total, winning by a shot from Englishman Tommy Fleetwood (71) and Pole Adrian Meronk (66).
“I've been grinding for a long time and seeing Rasmus win three times made me want to do it even more. To finally get it done is very special.
“I'm very happy that Rasmus, his girlfriend and my girlfriend were around watching. I really appreciate it.”
A closing 67 that included six birdies saw Jamieson finish in a tie for eighth on nine-under, lifting hm 24 spots to 109th in this season’s Race to Dubai.
“This helps me out nicely in terms of the bigger picture for me this year,” said the 37-year-old, who is bidding to hang on to his card for the 12th successive season. “It’s been a good week and nice to be playing a bit better.”
Recent first-time winners Grant Forrest and Calum Hill both closed with 66s to finish alongside each other on three-under, tying for 34th.