Yom Kippur War: Israel vs. North Korea
At the outbreak of the Yom Kippur War in 1973, North Korea was quick to confront Israel by sending 20 combat pilots and 19 ground personnel to Egypt. The North Korean MiG-21 Fishbeds engaged Israeli F-4 Kurnass (Sledgehammer) fighters up to six times during the conflict, but one fight stood out over the rest.
The last aerial battle over Egypt, on October 6, 1973, was when a group of four F-4s were on patrol near the Gulf of Suez. When they were almost out of fuel and ready to head home, they spotted a pair of MiG-21 Fishbeds heading through the clouds. One vanished, but there was no escape for the other. With the help of a friendly Ground Control Intercept (GCI) station, the Israeli jets locked on and fired three AIM-9D Sidewinder missiles. The missiles all detonated close to the MiG, but it kept on flying. Low on fuel, the Israelis were forced to return home without the kill. Just before they were out of sight, an Egyptian SAM was launched into the sky but accidentally hit the North Korean MiG, finishing it off.
It wasn’t until after the war the Israelis learned that they’d been fighting with the North Koreans. (Source)