In front of an exhausted London crowd that was still awaiting a far more anticipated semifinal match to come - Rafael Nadal vs Novak Djokovic - Anderson eventually got Isner to blink, breaking his serve and going on to win, but needing 50 games in the final set that eventually ended, 7-6 (6), 6-7 (5), 6-7 (9), 6-4, 26-24.
Melichar and Peschke will play the victor of the second semifinal between No. 3 seeds Barbora Krejcikova and Katerina Siniakova of the Czech Republic and the unseeded pair of Alicja Rosolska of Poland and Abigail Spears of the U.S.
Those named Kevin Anderson are being offered a free "victory feast" for them and two friends - in honour of his three-set victory. On the pro tour, Isner held the decided edge in their matches with an 8-3 record. Anderson won the opening set before Isner bounced back to take the next two.
After each of his service games, Isner was one game away from the win, which was likely more agonizing than helpful, especially as Anderson continued to pummel aces and winners to bring things back even.
The reason the match went on for so long comes down to one of Wimbledon's quirks - a five-set match can not end on a tiebreaker, a tradition shared at the French Open and the Australian Open.
Isner double-faulted to set up a set point for Anderson when serving at 5-4, but he saved it with a 129 miles per hour second serve that the South African couldn't return.
In a match between two of the game's biggest servers, Anderson started the match with a double-fault. Brian Norton was the last South African man to reach the final in 1921. Djokovic owns 12 Slam trophies, three from Wimbledon. In his final Collegiate season in 2007, John Isner led his team towards the NCAA Division I Men's Tennis Championship title, defeating the University of Illinois Fighting Illini 4-0 at home in Georgia.
This is the first time in the professional era that all four male semifinalists at a major are older than 30.