MAY 4, 1942: Allied and Japanese forces clash at the Battle of the Coral Sea in the first engagement between opposing aircraft carriers. Alerted of Japanese plans to invade Port Moresby in New Guinea and nearby Tulagi, Allied naval ships and American carrier-based planes attacked the landing force, prompting the Japanese commander to send in his own carriers to seek out the American task forces. For two days the opposing carriers launched repeated attacks, with American planes sinking the Shoho and heavily damaging the Shokaku, while Japanese planes strike the USS Yorktown and mortally wound USS Lexington (pictured), before both fleets withdraw. The loss of a fleet carrier and many aircraft by the Imperial Japanese Navy would even the odds in the pivotal Battle of Midway the following month, where American air power would win a decisive victory.