Nadal grabbed the fourth set to set up a monumental 91-minute decider that Djokovic clinched when Nadal fired a forehand wide.
Upon resumption of the match on Saturday, Nadal broke Djokovic in the second game to lead 2-0 but dropped his own serve in the fifth game.
Anderson, 32, will vie for the title on Sunday against the victor of the match between Nadal, the world No. 1, and three-time champion Novak Djokovic.
Following a three-year wait for Djokovic and Nadal to continue their Grand Slam rivalry and then an afternoon caged in the locker room while the Anderson and Isner marathon unfolded, they were finally let loose at gone 8pm with the roof closed.
Afterwards, Anderson told the BBC: "I don't know what to say, just playing in those conditions was really tough on both of us".
Djokovic has already hit 42 winners to Nadal's 39 but has converted just two of 10 break points.
Of the task against Anderson, Djokovic said: "Hopefully we can first of all play, both of us get out on court".
In the fifth set, Anderson broke Isner's serve at 24-24 to take command. The Serb had two more break points to level proceedings again when Nadal was serving for the set, but could not convert them and the Spaniard made it 1-1, winning the set 6-3. "I'm trying to digest that first, enjoy it, and we'll think about the next one".
Raonic, the 2016 Wimbledon runner-up, was a point away from taking a commanding two-set lead.
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Serbia's Novak Djokovic, seeded 12th, defeated World No.1 Rafa Nadal in a five-set thriller on Saturday to reach the Wimbledon final against South African Kevin Anderson.
In a contest pitting two of tennis' biggest servers on Wednesday, Isner was out-aced by a tally of 31-25 but did not get broken once during the two-hour, 42-minute match, reports Efe. "In the end someone has to win", Anderson said, "I feel for John, I don't know what I might have felt at the end of such a long match, to not win".
"It's been a rollercoaster ride for him but he had a day off".
"For the first time in my life I have someone screaming, 'Daddy, daddy, '" the champion said, as the camera zoomed in on his son and wife clapping in the crowd. "I'm going to have to recover as much as I can and to try to be as ready, as fresh as possible".
"I apologize I'm not more excited right now", he continued.
With the increasingly physical nature of rallies, the advances in training and nutrition that help extend careers, and the dominance of a certain trio of all-time talents Federer has 20 Grand Slam titles, Nadal 17, Djokovic 12 it's been hard for any youngsters to elbow their way to the top.
Isner fell despairingly short in his bid to reach a first grand slam final at the 41st attempt.
Anderson, who had the doctor on court as early as the fifth game of the match, complaining of what appeared to be dizziness, came from behind to win the first tiebreak of the match.
When Kevin was 12 years old, he used to compete against Spanish tennis star Rafael Nadal on the juniors circuit.