LONDON (AP) While most eyes were on the Williams sisters, CoCo Vandeweghe and Madison Keys quietly showed there are more American players to pay attention to at Wimbledon.

Vandeweghe and Keys both reached the quarterfinals for the first time at the All England Club, wrapping up their victories on outside courts just as Serena Williams' match against sister Venus was getting started on Centre Court. With Serena also winning, it's the first time since 2004 that three American women have made the last eight at Wimbledon.

''It's been a while since there has been that many Americans in the second week, and it's just really exciting,'' said Keys, who beat Olga Govortsova 3-6, 6-4, 6-1. ''I think it's going to kind of inspire everyone else to keep doing well and keep working hard. ... It's great that CoCo went out and won today as well.''

Or, as Serena put it: ''Three out of eight is pretty good.''

Vandeweghe knows she can't ride anyone else's coat tails, though.

''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,'' Vandeweghe said. ''Because it's not a team sport. At the end of the day, it's an individual sport.''

Unlike Serena, the 20-year-old Keys and 23-year-old Vandeweghe will both be underdogs in the next round. Vandeweghe faces Maria Sharapova, the 2004 champion and former No. 1, while Keys is up against Agnieszka Radwanska of Poland, who lost to Williams in the 2012 Wimbledon final and reached the semifinals in 2013.

Vandeweghe had never been past the third round of a Grand Slam before Wimbledon, while Keys made the semifinals of this year's Australian Open before losing to Williams.

Vandeweghe advanced despite what she called ''one of my worst matches that I played the whole tournament so far,'' and knows she needs to play a lot better against Sharapova.

However that match goes, though, Vandeweghe is likely to keep smiling - just as she did even when things weren't going well on Monday.

''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.''

Vandeweghe and Keys are part of an exciting new generation of American players that also includes Sloane Stephens and Christina McHale.

They all grew up watching the Williams sisters who - as their match on Centre Court showed - are still setting the standard.

''They are both amazing champions,'' Keys said. ''They are doing so well even later on in their careers. I think it is inspiring to us thinking, you know, we have all of this time, but at the same time seeing them do so well from young ages is also motivating to see if we can do the same.''