As week two began in London, spectators were treated to a much anticipated Williams sister match and more upsets as the draw whittled down to eight.

Serena defeats Venus

Serena and Venus Williams have faced each other 25 times during careers that span back to the 1990s. Remarkably, the sisters have combined for 27 major championships, including 10 Wimbledon titles. Serena came into their quarterfinal match holding a 14-11 head-to-head edge and was too much for her sister on Monday, advancing 6-4 6-3.

Both players struggled to hold serve early in the first set. But Serena gained control of hers as the set advanced and scored a key break midway through to gain an advantage. As she began to serve more consistently and win most of her first-serve points, Venus could not make a dent against the younger Williams.

In the second set, Serena clearly began to dictate the momentum and became more aggressive from the baseline. Firing strong, crisp shots, she gained clear control of the set and never relinquished it. She cruised to the straight-sets victory, keeping her run for history alive. Finishing with 36 winners to just 13 unforced errors, Serena turned a highly anticipated match into another business-as-usual performance in just over an hour.

Serena praised her sister after the match. “I always say I wouldn't be the player I am today if it wasn't for Venus,” she said. “Just having an opportunity to watch her win matches, watch her go to the top, and me wanting to be there because she was there. Her practicing next to me on the court. That inspiration, her inspiring me. Venus does nothing wrong. She's like the perfect sister.”

Muguruza upends Wozniacki

When Petra Kvitova lost in the round of 32, the draw opened up for 5th seed Caroline Wozniacki. The Dane became one of the favorites on the heels of her quality tennis in the first week. With Wozniacki the only top-10 seed remaining in the bottom half, the planets seemed to be aligning for the former world No. 1. Then came Garbine Muguruza.

The Spaniard would put a firm end to any talk of Wozniacki and a title in London with an impressive 6-4 6-4 victory. Muguruza was aggressive in the first set against the counterpunching Wozniacki and seized her opportunity with the set’s only break.  That was enough to take the opening frame.

Wozniacki looked to gain an edge early in the second, but a poised Muguruza fought and turned the momentum around, gaining a late break of service during one of the more intense and compelling games of the match. With the set at 5-4, she would close out the match on her serve, advancing to the quarterfinals.

Muguruza reflected on her performance afterwards, observing “I went into the match very focused and prepared because I knew that she was going to try to make it a long and physical match against me. So I think I used my opportunities on the short balls. I think I played really well. This helps me a lot against these kinds of defensive players.”

Vandeweghe breaks through and into the quarters

American Coco Vandeweghe continued her breakout performance on Monday with a 7-6 7-6 win against Lucie Safarova. Vandeweghe had never previously advanced past the third round of a major but has taken it one step further and will join the final eight.

Behind her big serve, the world No. 47 took the key points in a tightly contested match that featured two tiebreaks. The sixth seed entered Wimbledon after a run to the final at Roland Garros and was a semifinalist a year ago in London.

Vandeweghe noted her approach to matches as a factor in her success. ''I try to have a good time out there on the court, or at least fake it enough to where it looks like I'm having a good time out there,'' she said. ''I definitely am the type of person that likes to have a laugh at themselves, especially when it looks like I have done something stupidly ridiculous. I think that relaxes me instead of keeping it pent up and at a shorter fuse.''

The 23-year-old joined Williams and Madison Keys as a trio of Americans who have advanced to the quarterfinals. She was happy for her country and for herself as well, ''It's good to see other Americans doing well for the sport of tennis in the United States, but for me, it doesn't affect me either way,'' she said. ''Because it's not a team sport. At the end of the day, it's an individual sport.''

Other victors on Monday included fourth-seeded Maria Sharapova and 13th seed Agnieszka Radwanska.