I did automatch, but the game never started -- it's said "waiting for" (my opponent's name) for something like a half hour. refreshing the page doesn't help, nor does opening it in another browser. Hitting cancel doesn't help either.
solved with considerable difficulty if anyone else is having this problem: refresh, and hit the cancel button before it disappears
Or you can use incognito window and click "Kick & Resign" instead of "Login" after filling username and password.