There are a few problems with your question. There was a theory put forwards by E.R Dodds regarding the collapse of the inherited conglomerate (in his book (1952) The Greeks and the Irrational). The idea behind this was that as science became more prominent among intellectuals they distanced themselves from the religious masses. This caused tension throughout society and in the end the intellectuals capitulated and the Greek enlightenment died. Neo-Platonism was just fancy religion with no scientific merit. However there are a number of issues with this view. First is Dodds himself, and how his theory reads as a man trying to understand the 'epidemic madness' at Oxford during the build up to World War 1.

Second is the notion that science automatically equals the death of religion. The relationship between the two is more complex. To Jürgen Habermas (sociologist and philosopher) secularism arises due to scientific and theological advancement. Two recent books on the subject (Taylor's A Secular Age and Asad's Formations of The Secular) both argue that secularism needed Christian theology to begin (to Taylor, Christianity's ultimate triumph is that it then leaves while Asad argues that it sticks around in all but name). Very few sociologist stick to the idea that religion is dying (even in the west) and that this is due purely to advancements in science (for example see how Peter Berger, an early exponent of the secularization thesis, has recanted all the views he held in the 1970's). Religions don't die, they change.

Finally, the problem with pitting these two against each other is that the concepts are not well defined enough to be applicable to a different cultural contexts such as in the ancient world. To start it is worth repeating that there is no Greek word for religion. Religion as a neat category simply did not exist, it was ingrained in every aspect of life (Asad's Genealogies of Religion argues that Religion only becomes a separate category in light of the Protestant reformation). Then there is the difficulty of discussing science and rationality. Oswyn Murray (and then Tom Harrison) argued that the thing we count as Greek religion was more rational than the thing we count as Greek science because there is a greater attempt to find coherence or Zweckrational in the former than in the later.

So in short discussing an opposition between ancient science and religion, and citing one as killing the other, imposes too many modern conceptions of a (now) out-dated secularization model.