Had two incidents like this, the first incident shorted out my phone (just one second in the water), the second one I wiped dry, wrapped a piece of cloth around it and put it in a sack of rice to absorb the moisture (googled it).
Moral of the story: Never turn on a wet cellphone immediately (even after wiping it dry) lest you want a shorted out unit.
Dunno if doing the latter will make much difference seeing as you turned it on and charged the unit. If it is still under warranty you can try to have it fixed, just don't mention the water incident (though there is a possibility they might find out even after it's dried, dunno really)
Xperia Active ST17i