The Gemara (קידושין כט) relates a story about Rav Acha Bar Yaakov. One day he came to the city of Abaya to learn Torah from him. At that time there was a 'mazik' in the beis midrash, and many people were being harmed, therefore nobody would enter the beis midrash. Abaya told the townspeople not to offer Rav Acha lodgings so that he would be forced to sleep in the Beis midrash, and thus kill the 'destroyer' who was wreaking havoc there.
Indeed, when R' Acha went into the Beis midrash he saw the mazik in the form of a crocodile with 6 heads. Each time that Rav Acha bowed during his tefillos the crocodile lost one head, until it eventually lost its power completely and died.
The Maharsha asks: how could Abaya rely on the fact that Rav Acha will have the power to destroy the destroyer, perhaps he was putting his student's life at risk through sending him into the Beis midrash? Additionally, when one is granted a nes, it reduces his zechuyos, hence he was diminishing the merits of Rav Acha. The Maharsha answers that Abaya relied specifically on the tefillos of Rav Acha and when one is granted salvation through tefillah, it is not considered a nes. Hakadosh Baruch Hu has granted us the power to change a situation through tefillah, and being that it is part of the natural course of the world, it is not considered a miracle!
In the final pesukim of the Torah it says לֹא קָם נָבִיא עוֹד בְּיִשְׂרָאֵל כְּמֹשֶׁה אֲשֶׁר יְדָעוֹ ה' פָּנִים אֶל פָּנִים (דברים לד י-יב) and there will not be another prophet in Yisroel like Moshe, who spoke face to face with Hashem. The Ramban explains that the difference between Moshe and our other great prophets such as Eliyahu and Elisha Hanavi was that the other Nevi'im brought about miracles through their power of tefillah, whereas Moshe who was the conduit for great miracles without tefillah. Only Moshe had the unique power to bring nissim without prayer because miracles brought about through tefillah are essentially natural occurrences! Obviously, it is not within our understanding to compare these great prophets of Yisrael, but we can glean from this how Hashem gave tefillah the power to completely reverse the order on nature.