Chrome won by being unethical (and continuing to do so), for a while every time you visited some Google site you were bombarded with "switch to Chrome" banners.

Chrome won by being unethical (and continuing to do so), for a while every time you visited some Google site you were bombarded with "switch to Chrome" banners. At the same time they often artificially slow down Firefox on Google sites (see e.g. the recent news about some code on YouTube)