Serena Williams has overwhelmed Spain’s Carla Suarez Navarro 6-2 6-2 to reach her 14th Wimbledon quarter-final where she will not have to face top seed Ashleigh Barty.

The world No.1 was shocked by Williams’ compatriot Alison Riske 3-6 6-2 6-3 earlier on Monday, leaving Czech ace Petra Kvitova as the only top seed left on the 37-year-old’s side of the draw.

“She’s (Riske is) great on grass and just took out the world No.1… I watched that and I’ll be ready,” Williams said.

The American, aiming for a record-equalling 24th grand slam title, produced 19 unforced errors on Centre Court, including a bizarre mistake when she leaned over the net to hit a volley and had the point docked.

But she also conjured 21 winners, some of which left the crowd gasping in admiration and her 30-year-old opponent helpless on the other side of the net.

Williams, seeded 11th, had little match practice coming into Wimbledon because of injury and teamed up with Andy Murray in the mixed doubles to get some more playing time.

“I’ve had more matches this week than the past five months but it’s definitely good and I know I can play and I’m now physically better (so) it’s almost a feeling of relief more than anything,” she said immediately after coming off court.

Earlier, bidding to become the first Australian woman to make the quarter-finals at the All England Club since Jelena Dokic 19 years ago, Barty fell to free-swinging Riske.

The unseeded American withstood 12 aces from Barty to chalk up her tour-best 14th grasscourt victory of the season.

The Court 2 boilover also ended Barty’s 15-match winning streak and scuppered the 23-year-old’s hopes of completing a rare French Open-Wimbledon title double.

“I didn’t win a tennis match. It’s not the end of the world. It’s a game. I love playing the game. I do everything in my power to try and win every single tennis match. But that’s not the case,” Barty said.

“It’s disappointing right now. Give me an hour or so, we’ll be all good. The sun’s still going to come up tomorrow.”

Meanwhile, Ukrainian eight seed Elina Svitolina and China’s Zhang Shuai progressed to the quarter-finals.

Svitolina dismissed Czech Petra Martic 6-4 6-2, while Zhang prevailed 6-4 1-6 6-2 against Svitolina’s compatriot Dayana Yastremska.

Czech Barbora Strycova is also through to the next round after the 33-year-old eliminated Belgian 21st seed Elise Mertens with a 4-6 7-5 6-2 triumph.