It was a case of down but definitely not out as a Rafael Nadal kept picking himself off a slippery and dusty Centre Court surface to storm into the Wimbledon semi-finals with a pulsating 7-5 6-7 (7) 4-6 6-4 6-4 over Juan Martin del Potro.
In a match suspended from Monday night due to darkness with the Argentine star two sets to one ahead, Del Potro sealed victory on a fifth match point after nearly four and a half hours of action on Court Two.
The Argentine next faces two-time champion Rafael Nadal, who has reached the Wimbledon quarterfinals for the first time since 2011.
Del Potro trails world number one Nadal 10-5 in career meetings.
In a match filled with entertaining rallies between two of the biggest hitters in the game, Nadal came from a set down to win 7-5, 6-7 (7), 4-6, 6-4, 6-4 in 4 hours, 48 minutes - the longest match of this year's tournament.
The Argentinian saved two break points in game eight but he fell short just before the tie break, allowing Nadal to convert a break point in game 12 for a 7-5. He must get past three-time champion Novak Djokovic in the semi-finals on Friday for another shot at the title. The set stayed on serve until Del Potro secured the first break point for a 4-3 lead.
Del Potro too noted the change in conditions but appeared to relish the chance to slide around a bit more on the grass.
'I am very happy the way that I survived a lot of important points in that fifth set.
Argentina's Juan Martin Del Potro celebrates winning his the fourth round match against France's Gilles Simon.
Nadal started strong on serve to power his way into a 3-2 lead during the opening set. Del Potro, who sprayed his once pained wrist with a powder on most changeovers, had new shoes brought to him after the seventh game of the fourth set.
"Rafa is a fighter". The hard-serving American beat Milos Raonic of Canada 6-7 (5), 7-6 (7), 6-4, 6-3 to set up a meeting with Federer's conqueror Kevin Anderson in the last four.
Isner has yet to be broken at this year's tournament and saved the only break point he faced.