VIDEOS:
Five Ends, Six Begins
The final part of "The Caves of Androzani", and by extension the final episode of the Peter Davison era, ends with the regeneration of the Fifth Doctor and the introduction of the Sixth. Fitting this, the closing credits paste Colin Baker's face (a recreation of the episode's final shot) atop Davison's.
Example of:
Finale Credits
Example of:
The Nth Doctor