London: Serena Williams declared herself ready to roll in her Wimbledon quarter-final showdown with Victoria Azarenka, while Maria Sharapova is wary of surprise package Coco Vandeweghe in Tuesday`s last eight clashes.
Williams said she feels comfortable once she makes the last eight of a Grand Slam, while Azarenka said she was still searching for the key to unlock the world number one`s defences.
The winner will face either fourth seed Sharapova or unseeded American Vandeweghe in Thursday`s semi-finals.
All eight Wimbledon quarter-finalists from last year are out of the tournament, with Serena and Sharapova the only two from the world`s top 12 who are still standing.
That makes the bottom half of the draw appetising for Agnieszka Radwanska, the Polish 13th seed, who takes on US number 21 seed Madison Keys.
The winner would face either Swiss 15th seed Timea Bacsinszky or 20th seed Garbine Muguruza of Spain in the semis.
Williams, who downed her sister Venus to secure a quarter-final spot, is in confident mood.
"I feel like my tournament has finally begun. This is where I feel really comfortable in a Grand Slam," the US, Australian and French Open champion said.
"I`ve had a couple of tough matches with Victoria. I`m going to be ready. I`m going to have to be ready. She`s due to win big and to do really well. Incidentally -- so am I.
"I`m just going out there and doing the best I can. I hope not to have a bad day. I have three rounds to play."Williams, 33, has a 16-3 record over Azarenka. The Belarusian 23rd seed, who won the 2012 and 2013 Australian Opens, has never beaten the US 20-time Grand Slam winner at any of the four majors.
"The key is for me, I still need to find it because I haven`t beat her in a Grand Slam. I still have to find that extra step to go a little bit further," the 25-year-old said.
"She`s a great player. One of the greatest of all time.
"I just try to really focus on what I have to do instead of thinking who is on the other side and try to execute my game."
Meanwhile Sharapova, a five-time Grand Slam winner, paid tribute to her quarter-final opponent Vandeweghe.
The world number 47 has dumped out seeds Karolina Pliskova, Samantha Stosur and last month`s beaten French Open finalist Lucie Safarova.
"It`s been a tremendous effort for her to get to this stage of the tournament," the 2004 Wimbledon champion said.
"It`s always tricky playing against a really good server on grass because a few points here and there can ultimately tell the difference in the winner and the loser."
Vandeweghe, who had never been beyond the third round of a major before this year`s Wimbledon, said she would try to play things cool.
"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," the 23-year-old said.
"That relaxes me instead of keeping it pent up and at a shorter fuse."While Williams, Sharapova and Azarenka have 27 Grand Slam titles between them, Radwanska, the 2012 Wimbledon runner-up, is the only one in the bottom half who has even been in a major final.
She faces Keys, who made the Australian Open semis in January.
"It couldn`t be any better," said Radwanska. "I`m really playing on a really high level right now."
Keys also acknowledged how well the Pole is playing.
"She`s an incredible fighter. She is a great mover, and her hands are unbelievable. She makes you play four extra balls. She`s a really tough opponent," the 20-year-old said.
The winner faces either Muguruza, who is playing for only the third time at Wimbledon, or Bacsinszky, in the semi-finals.
The Swiss, who reached her first Grand Slam semi-final at the French Open last month, said it did not matter that one out of her, Muguruza, Radwanska and Keys would reach the Wimbledon final.
"Top 10 or not, there are great players out there," the 26-year-old said.
Muguruza knocked out former world number one Caroline Wozniacki for her quarter-final place.