But at 6-10 (Isner) and 6-8 (Anderson), their games are also as similar as the two sides of a Rorschach print, relying heavily on a massive serve and forehand.
Anderson then took the fourth set 6-4, breaking the Isner serve twice in the set.
That inconsistency was eliminated in an absorbing final set before Anderson produced a moment of magic. Djokovic owns 12 Slam trophies, three from Wimbledon.
It was, inevitably, a match of big serves galore, with an 129mph second serve from Isner a highlight, but both offered plenty off the ground too in an engaging five-set encounter.
While one might think that such a closely fought match was an enthralling display of athleticism, as the game teetered back and forth in the fifth set, the opposite was true.
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Isner is best known to many fans, particularly in Great Britain, for his astonishing contest with Nicolas Mahut on Court 18 at Wimbledon in 2010.
Anderson had break points in the 15th, 21st and 35th games of the decider before taking victory when a tired Isner hit long.
Isner was serving first, with Anderson then having to hold each time in order to stay alive in the match. The fifth set alone contained the number of games that would typically take up four sets. Isner and Anderson have played each other before professionally and they were rivals in college (Isner, 33, played at the University of Georgia, and Anderson, 32, at University of Illinois).
Nadal and Djokovic will battle for Sunday's final on the same court at 4pm.