After an epic lightsaber duel, Bastila began cutting off Grievous' hands one-by-one. When he was down to one, he lifted the young jedi by her throat causing her to drop her saber. Bastila tried to Force push the General away, but he dug his feet into the arena ground.
"Hahahaha! You are a fool Bastila. What Revan saw in you I shall never know!"
After a few seconds of struggling, Bastila calmed herself by repeating the Jedi Code in her head.
There is no emotion, there is peace.
There is no ignorance, there is knowledge.
There is no passion, there is serenity.
There is no chaos, there is harmony.
There is no death, there is The Force.
I know what I must do. I hope I don't regret this later.
Bastila used Force Lightning on Grievous, freeing herself. She pulled her lightsaber into her hand and stabbed the General in the heart. He fell.