Navigating relationships with coworkers

Hi, I’ve been working with Jason for about 6 months now, and we’ve become pretty good friends. Recently, though, I’m starting to feel like there’s some tension. We’re both up for the same promotion, and I’ve noticed he’s been acting differently around me—more distant and competitive. I really value our friendship, but I also want to maintain professionalism. How do you navigate a relationship with a coworker when there’s a blurred line between friendship and competition?