Anything can happen. I see 3 scenarios
1) Jake will start running and making Mike tired. He will try to use his age advantage. In late rounds he will do some damage to slowed Mike. Probably Mike will have a cut. And it will be a Jake winning by split decision
2) Jake will start with furious actions from very start. His goal will be to surprise Mike, who hasnt been in real fight for years. With enough unaswered punches, Jake could take some rounds (especially if he manages to daze Mike), and then survive till the end and win by decision.
3) Mike, as more experienced, will block avoid and wait, and later land either a body punch and win by TKO, or will win by TKO after Jake would had two knockdowns in one rounds. I really doubt that ref will allow a clear knockout, and Jake would be so silly to walk with hands down against such a striker.