Edit: PLEASE, if you don't read ANYTHING ELSE read this: <link> This link is from the official Sage site about rods breaking and why they do! Very informative!
On a heavier rod, as most if not all of you know, there's a thing we all love and it's called the fighting butt. It's called that for a REASON! You put it on your hip and acts as leverage when fighting a fish. However, as I mentioned, most people want to hold the blank as well as the handle of the rod itself. It feels more comfortable to them but it's a no no. Have I stressed that enough? : )
Here is a post about why leverage is so important in fly fishing much less fishing period! It goes in depth but it really is excellent when you read the entire thing. Seriously, I learned from it even though I do fight with the rod from side to side and not straight up in the air.
There was another GREAT video of a guy fighting a giant salmon on a fly rod and was holding it by the blank. Literally broke in half. Then again, he was fighting it with the tip and not the butt section.
Bottom line: don't be stupid. Play the fish out. Mind your P's and Q's because the fish is FIGHTING FOR ITS LIFE! Use the butt section of the rod for leverage instead of the tip. Comment if you wish on how you play a fish out whether big or small!