Serena Williams overcame the biggest test of her return to Wimbledon as she came from a set down to beat Camila Giorgi and make the semi-finals.
The seven-time champion, who missed the tournament last year as she was pregnant with daughter Olympia, was outplayed by Italian Giorgi in the first set.
But Williams rallied to win 3-6 6-3 6-4 on Centre Court and then insisted she was never worried.
"No. It's weird," said the 36-year-old American. "Sometimes I feel, 'man, I'm in trouble'. Sometimes I feel I can fight.
"But for whatever reason I was so calm. Even when I was down the first set, I thought, 'Well, she's playing great. I'm doing a lot of the right things. It is what it is.'
"I'm not tired at all. In fact, when I was out there I think that was one thing that was surprising, how well I felt.
"Not once was I out of breath. Sure, there weren't a lot of long points, so maybe that's why I wasn't out of breath. But I felt good."
Williams will next face Germany's Julia Goerges, the 13th seed, who reached her first grand slam semi-final with a 3-6 7-5 6-1 victory over Dutchwoman Kiki Bertens.
Another German, Angelique Kerber, admitted nerves almost got the better of her after needing seven match points to see off Daria Kasatkina.
Russian youngster Kasatkina broke back when Kerber first served for the match, and then saved six match points during an epic final game.
Kerber came out on top in a spectacular 25-shot rally to force match point number seven and finally got the job done as Kasatkina netted a forehand, the German a relieved 6-3 7-5 winner.
"Of course, it's not so easy because you feel your nerves," said Kerber.
"You feel you get a little bit tight, especially if you have your third or fourth match point again.
"We both played at a really high level, starting from the first point. The last game showed how good we both played and how she was fighting until the end."
Seeded 11th, Kerber seems to be approaching something close to her 2016 peak, when she won her two grand slam titles and reached the final at Wimbledon.
The 30-year-old slipped out of the world's top 20 after a miserable 2017 but has rediscovered her game this year.
"I'm looking forward now to playing the semis here," she added. "That is where I put my focus on right now, not about the results I had before. It's just about the next match now."
That next match will be against another 21-year-old in 12th seed Jelena Ostapenko, who beat Dominika Cibulkova.
The Latvian struck 32 winners to just six from her opponent, with Cibulkova's second serve taking a pummelling, and won 7-5 6-4 in an hour and 22 minutes.
"I knew I had to be aggressive otherwise she would have opportunity for winners so I just went for my shots," Ostapenko said.
"Angelique is a great player, it's going to be a battle, a tough match probably with long rallies, but I will prepare well and be confident."
