Buck Rogers in the 25th Century: Planet of the Slave Girls (1979)

The majority of Earth's fighter squadron becomes incapacitated after using poisoned food discs. Buck, Wilma and Duke Denton fly to the distant planet of the food's origin, Vistula. They seek to track down a slave trader named Kaleel, who is collaborating with the planet's governor. While on the planet Vistula, they find that Kaleel has been building a fleet of attack ships in secret, and plans to use them against Earth's weakened defense forces. With Earth's defense force now heavily outnumbered 10-to-1, Buck decides that he must destroy the attack fleet and rescue Wilma, who has become trapped in Kaleel's mountain fortress. It originally aired as a 120-minute episode, but has been formatted as two 60-minute episodes in most subsequent re-airings for scheduling reasons. While many guides list it as a two-parter, its initial airing and release on DVD as one double-length episode should make this the official recognition.