The fights are becoming more common:

Unfortunately for a 13-foot (4-meter) Burmese python in Florida's Everglades National Park, eating the enemy seems to have caused the voracious reptile to bust a gut—literally.
Wildlife researchers with the South Florida Natural Resources Center found the dead, headless python in October 2005 after it apparently tried to digest a 6-foot-long (2-meter-long) American alligator. The mostly intact dead gator was found sticking out of a hole in the midsection of the python, and wads of gator skin were found in the snake's gastrointestinal tract....
Clashes between alligators and pythons have been on the rise in the Everglades for the past 20 years. Unwanted pet snakes dumped in the swamp have thrived, and the Asian reptile is now a major competitor in the alligator's native ecosystem. (See "Huge, Freed Pet Pythons Invade Florida Everglades.")
"Clearly if [pythons] can kill an alligator, they can kill other species," Frank Mazzotti, a University of Florida wildlife professor, told the Associated Press. "There had been some hope that alligators can control Burmese pythons. … This [event] indicates to me it's going to be an even draw."