Duran ko 15 Ortiz Lopez ko 15 Ayala Leonard ko 15 Benitez Benitez ko15 Villa Sandoval ko 15 Chandelier
Kates-Galindez I was officially at 2:59 of the fifteenth round, so impossible to beat in that regard (and never matched as far as I know).
Depends what you mean by 'late': Scheduled distance 'late' has seen probably the best examples already posted, but talking latest as in longest, in the glove era Johnson/Willard is up there at Heavyweight.
Shannon Briggs TKO'd Liakhovich in the last second of the last round to win the WBO Heavyweight title