"If I were to have won, I would have a very tough task, too", Isner said.
"Just playing like that in those conditions, it was really tough for both of us".
"Honestly, I really hope this is a bit of a sign for grand slams to change the five sets". They combined for 102 aces: 53 by Isner, 49 by Anderson.
Isner, who said Wimbledon had become "a house of horrors" for him since his 2010 match, had been trying to become the first American to reach the finals since Andy Roddick in 2009.
That moment, which took 99 grueling games to reach, sent the 32-year-old South African through to the final on Sunday, where he will play one of two legends of the sport, Novak Djokovic and Rafael Nadal.
The pair will face off for a record 52nd time in their careers in the other men's semifinal on Friday evening.
Both players are making their 10th appearance at the All England Club.
Only the U.S. Open has a tiebreaker fifth-set format.
At one point in the fifth set, a spectator shouted, "Come on, guys!"
If Kevin Anderson was facing John Isner in the first week of Wimbledon, it's hard to imagine it being played any higher than Court 18 and yet the big-serving duo thrashed it out on Centre Court in the semi-finals.More news: Partisan Divide Deepens Over Trump’s Supreme Court Pick
But in spite of that extra time Anderson will have to recover, Isner reckons the 6ft 8in player will still struggle to match the level of physicality no matter whom he plays against.
That service hold - helped by a 129 miles per hour (207.6km/h) second serve - took the American to 100 service games unbroken at this Wimbledon.
But the other three Grand Slam tournaments all play on until one player wins by two games.
The match was ironically labelled "pointless" by viewers who complained Anderson would be left worn out for Sunday's final. Isner wasted a set point in the opener.
That point ended up actually setting up the winning break for Anderson.
He couldn´t capitalise, however, and was broken straight back before Isner claimed the ensuing tiebreak having saved two set points.
The American fends off another break chance at 10-10 and this insane encounter has turned into the longest Wimbledon semi-final in terms of time and the number of games, passing the insane semi-final clash between Goran Ivanisevic and Richard Krajicek that Goran won 15-13 in the fifth.
"At the end, you feel like this is a draw".
The world was a demonstrably different place when Kevin Anderson and John Isner first took the court Friday for what would become a marathon Wimbledon semifinal.