For a lazy Ian who didn't attend extra class and has Jiujitsu 5, Kickboxing 2 and Athletics 6, this is a sequence that will get him a win without any RNG involved:
Round 1:
Guard
Attack -> Test the waters
Provoke -> Grapple -> Throw him -> Secure the position -> Tie him up
end of round: Ian score 3, tired 0. Rival score 2, tired 4
Round 2:
Block
Attack -> Grapple -> Shoot directly -> Slam him -> Go for submission -> Get up (or spend a will point to end right there)
Dodge -> Block -> Protect your body
Attack -> Attack -> Reverse the position -> Rest -> Pin him down -> Go for submission
end of round: Ian score 10, tired 1, hurt 1. Rival score 7, tired 5, hurt 4
edit: alternative version to end round 2 quicker, if one isn't interested in making it more flashy
Block
Attack -> Grapple -> Shoot directy -> Wrestle him -> Rest -> Pin him down -> Go for submission
end rount: Ian score 7, tired 0, hurt 1. Rival score 5, tired 4, hurt 1