Shane van Gisbergen earned the first win of his Xfinity Series career at Portland International Speedway on Saturday. After a late restart and a battle with Justin Allgaier, the Supercars champion took the Pacific Office Automation 147 checkered flag. Shane van Gisbergen wasted no time celebrating the milestone. He took a legendary victory lap, seemingly drifting around the entire 1.9-mile Portland road course. Fans will remember Shane van Gisbergen winning in his first NASCAR start ever. He took the checkered flag in rainy conditions at the Cup Series Chicago Street Race in 2023. Now, he adds…