Chevy Blazer won't turn over

Hello,
Glad I stumbled upon your site !!
I was jump starting another vehicle with my Blazer.
The other battery was quite dead so I jumped it for several minutes.
Both vehicles are in my backyard so I just left the Blazer running trying to start it. Got the vehicle started. Great, turned the blazer off. Later I tried to start the blazer, but it wouldn't turn over. It would act like it was getting fuel when I stepped on the accelerator, but then it would just die.
I changed the battery and the fuel filter. Engine runs a bit when I spray fuel in the throttle body. Is this just a coincidence that this happened, or did I do something ? It was working fine a few hours ago !...lol...Also I can hear the sound of the fuel pump working.
Any help would be appreciated !!