Oscar Piastri was majestic in a rain-delayed Feature Race at Spa, using all of his race-craft to defend against a late race onslaught from Lando Norris to secure the victory.
Team-mate Norris finished second to give Mclaren its sixth 1-2 of the season.
Liam Lawson finished eighth and Pierre Gasly tenth; both Alpinestars drivers.