It was the point in the Pacific war where the IJN never went on the offensive again. To me, that is a significant turning point bordering on miraculous.
Well their surface fleet did at Leyte and almost pulled it off except for Taffy 3 off Samar. Another fantastic battle by the greatest generation of sailors we shall ever see.
While the Japanese CAP was defeating every wave the Americans sent at their fleet, the successive attack waves were wearing down the Japanese air cover. In fact, cycling fighters off the flight decks was hampering the Japanese ability to spot and launch the next strike.
The real problem for the Japanese was that four carriers were not enough to subdue an island airbase covered by a mobile fleet of three carriers. The Japanese really missed the presence of Carrier Division 5, Shokaku and Zuikaku. In May and June 1942, Carrier Division 5 was the strategic margin held by Japan.
"In the first six to twelve months of a war with the United States and Great Britain I will run wild and win victory upon victory. But then, if the war continues after that, I have no expectation of success."
- Statement by Fleet Admiral Isoroku Yamamoto to Japanese cabinet minister Shigeharu Matsumoto and Japanese prime minister Fumimaro Konoe, as quoted in Eagle Against the Sun: The American War With Japan (1985) by Ronald Spector. This remark would later prove prophetic; precisely six months after the attack on Pearl Harbor, the Japanese navy would suffer a major defeat at the Battle of Midway, from which it never recovered.
IJN at the Battle of the Philipine Sea, June 19-20 1944 in an attempt to disrupt the battle for the Marianas.