Even the world's best players are not immune to crippling nerves as Iga Swiatek discovered when her Wimbledon dreams were turned to dust in a 7-5 6-7 (5-7) 6-2 quarter-final defeat by Ukrainian wildcard Elina Svitolina.
Svitolina, who returned to the tour in April after giving birth to her daughter last October, was 4-2 down in the opening set and struggled to get her serve going in blustery conditions on Centre Court as Swiatek moved into a 5-3 lead.
But the momentum suddenly swung Svitolina's way as from 0-30 down on her serve in the ninth game she went on to win 16 of the next 18 points to bag the first set and leave stunned Swiatek wondering what had gone wrong.
That sequence included breaking Swiatek's serve twice in succession, with the Polish top seed surrendering the first of those to love with a double fault.
After Swiatek guided a backhand volley into the tramlines to hand Svitolina the set, the players had to endure a 20-minute break as the roof was closed to shut out the dark clouds hovering over Centre Court.
That interlude gave Swiatek a chance to re-evaluate her tactics and she came back to break Svitolina for a 2-1 lead in the second set.
The top seed's 28-year-old rival, however, kept breathing down her neck and made it all square at 3-3 by pounding some ferocious groundstrokes from the baseline.
Swiatek earned two more break points in the ninth game but once those went begging neither player could break the deadlock and they headed into the tiebreak.
Svitolina made a fast and furious start to jump into a 4-2 lead but Swiatek, who saved two match points to beat Belinda Bencic in the previous round, refused to panic and kept faith with her fearsome forehand to rattle her rival.
A backhand error handed Swiatek the set and many thought Svitolina's moment to shine had come and gone as surely the world number one would now stamp her authority on the contest and race away with the decider.
But, having already beaten three Grand Slam champions in the run-up to her showdown with Swiatek, Svitolina had an appetite for beating more celebrated opponents and she was not going to let the Pole stand in her way as she targeted a place in the Wimbledon semi-finals for the second time in four years.
Svitolina kept believing as she broke for a 2-1 lead and then blew a hole in the aura around Swiatek, who was riding a 14-match winning streak which included her run to a third French Open title, after grabbing a double break two games later.
There was no coming back for Swiatek from that gaping abyss and a forehand into the net handed Svitolina a remarkable win.
World number four Jessica Pegula crashed out of Wimbledon after an untimely suspension of play helped shift the momentum in her surprise quarter-final defeat to Marketa Vondrousova.
The American looked poised to progress to the maiden grand slam singles semi-final of her career having overturned a one-set deficit to lead 3-1 in the decider.
But, due to forecasted rain, the contest was halted for around 23 minutes to allow the roof on Court One to be closed and 2019 French Open finalist Vondrousova returned to win five of the next six games to progress 6-4 2-6 6-4.
The Czech world number 42, who is enjoying her best run at the All England Club, will take on either world number one Iga Swiatek or Elina Svitolina for a place in the final.
"I don't know what happened," she said. "It's an amazing feeling, I cannot believe it."
Asked how much closing the roof helped her, she replied: "A lot actually. I never played on court number one under the roof. It's amazing.
"I just wanted to stay as long as I could and I fought until the end. She was pushing me to the edge so I am just so proud of my game."
She also revealed that an impromptu pep talk from her husband Stepan Simek during the unexpected stoppage helped inspired her stunning win.
"I actually didn't see my coach," said the 24-year-old of the weather delay. "I was alone in the waiting room.
"I chatted a bit with my husband. We talked on the phone. He just said, 'try to fight, you are playing good, you are playing a great match’.
"That was it. I think the break helped actually. It was good.
"She had break points for 5-1. You are not in a good mood. I just kept belief in myself.
"After the match point, I couldn’t believe it. I just couldn’t hold the tears."
