I'm not sure if this is a matter of the "decisive moment" or more a matter of scrambling to get a shot and actually getting it! Here is the caption Daniel Dolpire provided to National Geographic "Your Shot" when he submitted this photograph.
"I took this "once-in-a-lifetime" shot at Klein's Camp in the Serengeti, Tanzania. We came upon these lions at 7:17 in the morning. I scrambled for my two
camera bodies (Nikon D4 and D3s and 200mm-400mm and 500mm) and got the
shot! Exactly six minutes later the first lion got up and within another five minutes, three were sleeping and the
other three had gone off into the bush! I have been taking wildlife
photos for over 20 years, but this has got to be my special moment!"