By Mark Barden
BBC Sport at Wimbledon
Schuettler, aged 32, is currently ranked 94th in the world
Unseeded Rainer Schuettler will face Rafael Nadal in Wimbledon's semi-finals after edging past Arnaud Clement 6-3 5-7 7-6 (8-6) 6-7 (7-9) 8-6.
The pair resumed at one set all from the night before and suffered two rain delays in a match of over five hours.
The German, 32, took the third set despite allowing Clement to recover from 6-0 down to 6-6 in the tie-break.
They both broke again in the fourth and Clement levelled in another breaker but Schuettler finally won a tense decider.
The 30-year-old Frenchman, ranked 145th in the world, had looked second best to Schuettler who played with increasing confidence after play re-started at 1300 BST.
Schuettler surprised to reach semi
Neither man had previously reached the last eight at Wimbledon, although Clement is the reigning men's doubles champion with Michael Llodra.
Schuettler, like his opponent a former top 10 player but ranked 94th before Wimbledon, was on the verge of a 7-0 success in the third-set tie-break.
But Clement's recovery to 6-6 before losing 8-6 showed all his fighting qualities, and he gradually took control in the fourth set with his greater array of shots.
Having won the tie-break to level the match after a short rain delay, he broke Schuettler early in the fifth, only for the 32-year-old to break back again.
Schuettler then saved a match point at 5-4 before the heavens opened for a second time at 6-6 40-40.
When the players returned, 2003 Australian Open finalist Schuettler broke Clement again for 7-6 and served out to finally clinch victory in five hours and 12 minutes.
That duration tied the mark for the second longest men's match in Wimbledon history.
The longest remains Greg Holmes' 5-7 6-4 7-6 (7-5) 4-6 14-12 victory over Todd Witsken in five hours and 28 minutes in the second round in 1989 - a match spread over three days.
Schuettler said: "Honestly, it was really a strange match.
"I thought in the fourth set I had it, and then it changed the other way. So you never know.
"Even in the fifth, I was serving for the match. He had match point. So it was back and forth. Well, that's tennis. I'm sorry for him but I'm very happy that I made it."
Clement admitted his defeat was hard to take but said of his opponent: "We have a lot of respect. Honestly, I'm happy for him, because he is a very good guy."