On the last night of World War II, a Northrop P-61 Black Widow from the 548th Night Fighter Squadron from Ie Shima was on nocturnal patrol and in low-altitude pursuit of a Japanese fighter when the enemy aircraft hit the water before the Black Widow could fire a shot. The war officially ended at midnight that night, but there remained the possibility of kamikaze attacks on American airfields despite the surrender, so the P-61s remained on alert.
The following night on August 15, another P-61 was vectored by ground control on Saipan towards another Japanese fighter flying at low level. This time the Japanese pilot was dropping window to confuse the Black Widow's radar operator. Like the previous night, a low altitude pursuit ensued, but before the P-61 could open fire, the plane impacted the water.
The P-61 Black Widow in effect made the final two kills of World War II without firing its guns!
Source: Aviation History, November 2008. "Bite of the Black Widow: Northrop's P-61 was the ultimate nocturnal predator in the Pacific War" by Warren Thompson, p54-55.