Battle of the Coral Sea
The Japanese sank more ships than the U.S. However, the battle was considered a victory for the Allies because the Japanese forces were not able to capture the locations they were hoping to occupy.  As well, the Japanese carriers Shōkaku and Zuikaku were not able to fight in the Battle of Midway, which helped the U.S. to win there.  Japan's losses of carriers meant that they could not invade Port Moresby.  Two months later, the Allies launched the Guadalcanal Campaign.