Ryuk stayed at the top of his lifeguard thingie or whatever. Near, the little fatty, stayed at the wharf. If you pay attention close to the ending (sometime before the credits roll), you'll see Aizawa and Matsuda running along the path Light ran. Since Aizawa was ahead of Matsuda, he is first. Matsuda is second. Since no one else was seen running along that path, Light was third by default. I'm sorry it is hard to understand since it was inspired just by that one scene of Aizawa and Matsuda running =(