Anderson and Isner combined for 101 aces in a match that lasted six hours and 36 minutes with the South African eventually winning 7-6, 6-7, 6-7, 6-4, 26-24.
The 32-year-old will now either take on Rafael Nadal or Novak Djokovic in the final – they will likely have to play on Saturday to complete their semi-final.
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.
“He’s got a tough task ahead of him. If I were to have won, I would have a very tough task, too,” Isner said.
“Watching these guys, I was in the training room getting my blister taken care of, and they’re moving like gazelles out there. Djokovic is sliding all over the place.
“Whoever wins this match you would think, because of how much time Kevin spent on court, will be the prohibitive favourite.
“If Kevin can serve like that, serve a high percentage like he did, he could have his shot, for sure.
“He’ll do everything possible to get ready for Sunday.”
Isner had won the last five meetings with Anderson but their history together goes even further than their first professional encounter back in 2008.
The pair played multiple times on the NCAA college circuit including in the men’s team finals.
And the friendship and rivalry between the two was evident in both of their post-match interviews, with Isner quick to congratulate the South African for reaching his first Wimbledon final.
“He’s obviously a very good player, a contemporary of mine,” Isner added.
“We’ve been playing together for the longest time now. He’s someone that I have so much respect for because he works very hard at what he does.
“He’s someone that pushes me, I think. Maybe he’d say the same about myself. I mean, we’re about the same age. We’ve been doing this together for a long time.
“I see how professional he is. When I see him doing all the things that he’s doing, I think that’s a very good thing for me.
“It allows me to look at that and keep going, try to even work harder than he does, so…
“He’s one of the most professional players on tour. There’s a reason why he’s playing so well right now, because he does all the right things.”