Could 49ers have done more to run down clock?

I don't really watch football (or ant sport, really), and I only saw highlights of the game and not the game itself. But when I was watching the highlights, and the Chiefs had narrowed the lead to 20-17 and the 49ers had the ball with just a few minutes on the clock, I kept thinking, "Why aren't they just running out the clock?" Maybe I'm missing something (definitely possible when only watching highlights).