Rafael Nadal and Novak Djokovic have set up a box office Wimbledon semi-final but Roger Federer's title defence came to a screeching halt on a drama-charged day at The All England Club.
Federer squandered a match point and let slip a two-set lead for only the fifth time in his 20-year career as big-serving South African Kevin Anderson notched a famous 2-6 6-7 (5-7) 7-5 6-4 13-11 quarter-final triumph over the eight-times champion.
The 32-year-old's prize is a clash on Friday with first-time grand slam semi-finalist John Isner, who ousted 2016 runner-up Milos Raonic 6-7 (5-7) 7-6 (9-7) 6-4 6-3 in a serving shootout featuring 56 aces in four sets.
Only a spirited fightback from Nadal saved the Spaniard from suffering a similar five-set fate to Federer, the world No.1 scraping past Juan Martin del Potro 7-5 6-7 (7-9) 4-6 6-4 6-4 in a Centre Court classic.
Like Federer and Anderson, Nadal and del Potro Nadal slugged it out for more than four pulsating hours before Spain's 17-times major winner finally landed the knockout punch.
In one epic 14-point game early in the deciding set, such was the desperation of both combatants that del Potro twice left the ground trying to retrieve balls at the net before Nadal went hurtling over a barrier, into the stands and onto jaw-dropping spectators' laps.
When he finally prevailed after four hours and 48 minutes, Nadal - and del Potro - received a rousing standing ovation from the packed crowd including another living legend left-hander Rod Laver in the Royal Box.
Champion in 2008 and 2010, Nadal will face off with Djokovic for a record 52nd time on Friday after the Serb earlier ended Kei Nishikori's campaign with a controversy-laden 6-3 3-6 6-2 6-2 triumph over the Asian ace.
"A very emotional match. A great quality of tennis, especially in the last set, some amazing points,. Anything could happen," Nadal said.
"Very happy, a very important achievement for me to be back in the semi-finals of Wimbledon. Is an amazing feeling.
"Of course I'm sorry for Juan Martin. He's an amazing opponent, an amazing player."
But while Nadal and three-time champion Djokovic were expected to win, and Isner seeded to do so over Raonic, Anderson had never even extracted a set from Federer in four previous meetings.
But in a spectacular showing, the 2017 US Open runner-up reeled off three in a row to surge to within a match of a second grand slam final in 10 months.
An Anderson win looked anything but likely after Federer, once again looking imperious, extended his record streak of sets won at Wimbledon to an equal-career-best 34 straight to charge to a two-sets-to-love lead in little more than an hour.
But just as a record-extending 44th grand slam semi-final appearance beckoned, Federer blinked - and eighth-seeded Anderson seized the moment.
"Obviously I'm very ecstatic to get through that match," Anderson said.
"Beating Roger Federer at Wimbledon is definitely one I'm going to remember.
"I just kept on telling myself I have to continue believing.
"I just kept saying 'today is going to be your day'. You have to have that mindset.
"By the end I thought I did a great job not thinking about what was happening.
"That was a great performance from my side. I've put myself in with hopefully a shot to be playing again on Sunday."