Pettitte v. Carpenter, as the Astros try to clinch.
Going out a limb here, but I'm going to take the Cardinals in this one.
Pettitte still isn't 100%, from what I understand, and Carpenter has been great against the Astros, posting a sub-3 ERA against them in 2004 (albeit in just 2 games) and a 1.85 ERA in 39 innings against them in the regular season this year.
I think this series goes back to St. Louis for at least one more game...