Fresh off a Walker Cup victory, top-ranked amateur Jackson Koivun is making an instant impact on the professional circuit. He shot a 5-under 67 in the opening round of the Procore Championship in Napa, placing him in fifth. Despite a rushed practice round, Koivun carded eight birdies and showed the form that's already earned him a PGA TOUR card through the PGA TOUR University Accelerated program.