A single game lasts up to three rounds. To earn this easily, I turned on a second control and went to "Multiplayer> Local Match > HD Remix." I picked Ryu and Player 2 was Zangief. I walked up to player two and performed Ryu's throw (Hold towards/away and press Fierce Punch.
should be the default for Fierce Punch.)
Keep throwing Zangief until he dies. Repeat this the second round. After the second round is over, you should have this achievement. You can try letting Zangief win the second round if you want to get extra throws during the third round, but I was able to get it during round two.