It will be an easy win for Serena
Serena didn't play great as she already has 9 or more unforced errors. Still wins the first set 6-1. If I recall correctly she only had 2 service aces. Rain delay couldn't happen at a more opportune time for Radwanska as she'll get to talk to her coach and make strategy changes. Who knows maybe Serena's game changes too. However, I doubt it.
Serena needs an easy match as she has to play for the doubles championship today as well.
Serena will always have more unforced errors because she plays a high risk game. As long as her winners outnumber her errors, she is playing the right style of tennis. She must stay aggressive.