With her blend of flat forehands, slice backhands and net play worthy of her No.1 doubles ranking, the No.11-seeded Vinci was in control from the beginning against the No.18-seeded Cibulkova, needing just 68 minutes to complete a 61 64 victory. It was the Italian's fifth win in a row over the Slovak.
Having never reached the second week in her first 30 Grand Slams, Vinci has now gone this far at four of the last five - the fourth round of Wimbledon and quarterfinals of the US Open last year, and the fourth round at the French Open and Wimbledon this year. The only exception was at the Australian Open this year, where she fell to Elena Vesnina in the third round - and she had match point there.
Next up is No.6 seed Li Na, who had to battle to the ends of the Earth to outlast No.32 seed Klara Zakopalova, 46 60 86. After dropping the first set Li blazed through the second set at love in just 25 minutes but then had to grind out a marathon 57-minute third set, missing her first match point with a backhand long but converting her second one when Zakopalova hit a forehand into the net.
"She hits pretty flat and pretty deep - sometimes I felt like I had to dig my knees into the ground. Luckily there aren't so many players who play like her," Li said. "After the first set I was thinking I couldn't continue the same way. I had to change something. So I tried to come even more forward, and stay low, and after I broke her twice I think I probably had all the momentum to win the second set.
"The third set was so tough. I thought it was a really good set. And she served for the match, which was very tough. But I fought like crazy, and I'm very happy about how strong I was on the court.
"At least I'll be in the second week of Wimbledon now."
Li has beaten Vinci in all three of their previous meetings, though the first two were a long time ago and the third one - which Li won in three sets - came on the clay courts of Madrid just over two years ago.
"We've had so many years we haven't played - the last time was a long time ago I think," Li said. "And in the last two years both of us have improved a lot. And it's a different surface. She's always tough, and it's going to be a tough match, so I just have to rally and fight as hard as I can on Monday."
What does Li think about Vinci's game? "I saw her play a little bit today because when I was waiting for my match she was playing. She has a pretty good slice on the backhand. Not many girls use that, and it's going to be tough to deal with that shot, especially on grass courts. So again it will be tough.
"But that's the perfect thing about Grand Slams. You don't have to play every day. You have one day off so you can prepare your game for the next match. Everyone's different, so it's just perfect."
Another fourth round match set up on the top half of the draw was an all-unseeded one between Kaia Kanepi and Laura Robson. Kanepi beat American wildcard Alison Riske, 62 63, while Robson pulled off a big comeback, rallying from 61 53 down to beat good friend Marina Erakovic in three sets, 16 75 63.
"It's now my second time in the second week of a Slam, so that's pretty cool," Robson said after the match. "Except at the US Open I played on the Sunday, so it didn't quite feel like a second week, and my brother said it didn't count. But yeah, this time will be on the Monday, so that's pretty cool."
Robson and Kanepi will be playing against each other for the first time.