Clean pocket? Behave, did you watch the game. He spent almost the entire match running for his life, his evasiveness was the only reason he wasn't getting killed every other play.
The Niners front 4 were awesome, they made a good chiefs line look like the browns line.
If the Niners secondary had held up like the front they would have held on, the busted coverage for the Hill 44 yard pass (admittedly a brilliant pass) was a shocking lapse and proved the turning point.
Not saying the Shanahan calls and the Niners O get a let off as they were terrible down the stretch but Mahomes changes this against some great pressure.