The Danish 20-year-olds become the first brothers to win back to back events on the European Tour after Rasmus Højgaard won last week's Omega European Masters in Switzerland.
Nicolai Højgaard came into the final round with a one shot lead and had found himself two clear on the back nine before consecutive bogeys at the 14th and 15th wiped out his advantage and left him level with Tommy Fleetwood and Adrian Meronk going down the last.
He arrived at the 18th tee knowing he needed a closing birdie to win, and he did just that - holing from three feet to finish the tournament on 13 under par and clinch his maiden victory at this level, with Rasmus joining him on the green to celebrate.
Meronk and Fleetwood finished in a share of second place on 12 under just one shot behind Højgaard after posting rounds of 66 and 71 respectively, with Ryder Cup star Fleetwood also converting a must make birdie putt on the 18th green to tie Meronk's clubhouse lead before Højgaard had finished his round.
Home favourite Francesco Laporta was alone in fourth on 11 under after closing the tournament with a 68 to finish as the leading Italian, one stroke ahead of Edoardo Molinari.
European Tour