Hall of Fame
Keys played Bouzkova, Stosur, Collins and Kvitova. That's pretty much on par with Serena's opponents (Giorgi, McHale, Siegemund & Anisimova). Anisimova didn't play her best last night but part of that was because Serena didn't allow her to. Once she gets her service games under control she's going to be the real deal and I hope she comes back strong with a good run in Melbourne.You may want to get a little better look at how Maddison Keys is playing at the moment against much better competition.
That said we've seen this from Serena before where she can play lights out in earlier rounds but terribly in finals. It's clearly a mental issue more than a physical one despite her fitness not being at its peak.