I could be remembering it wrong but I think Lea got the last bow even toward the end of her original Broadway run (after Pryce left).
There's a plausible argument that The Engineer should be considered a featured role, but Pryce was considered leading and that's the category in which he won the Tony. Both Willy Falk, who played Chris, and Hinton Battle, who played John, were considered in the featured category that year.
"This is wanting something, this is reaching for it,
This is wishing that a moment would arrive.
This is taking chances, this is almost touching, what the beauty is." --The Light in the Piazza