MONTRÉAL, Canada - They're two of the most accomplished players on the WTA, they're good friends, they're both in top form - and on Friday Serena Williams and Caroline Wozniacki will be staring each other down and going to battle in the quarterfinals of the Premier-level Rogers Cup in Montréal.
The No.11-seeded Wozniacki was the first of the pair to advance, rolling past American qualifier Shelby Rogers - the player who took out No.5 seed Eugenie Bouchard earlier in the week - in just 56 minutes, 6-1, 6-0. Wozniacki has only lost a total of six games through three matches so far this week.
"It was a really good match out there today," Wozniacki said. "I felt really comfortable and confident. I served really well, returned well. Shelby is a tough player - she has some big shots out there - but I was able to just neutralize them and play my game, and I'm happy how the match went today."
Wozniacki is on an eight-match winning streak now - she went 5-0 to win her 22nd WTA title in Istanbul a few weeks ago, and three more wins this week have taken her to eight. And throughout that run it's become clear that her serving and returning have gone to another level - what clicked for her?
"I've just been serving a lot and returning a lot, really!" Wozniacki commented. "You kind of just get that feeling; you get in the zone. You know that you can pull it out when you need to.
"I think that's really the key. Just repetition, repetition all the time."
The former World No.1 will have to be on her game in the next round as she faces the current World No.1, Williams. The No.1-seeded Williams had a tougher day at the office but still managed to get through in straight sets, edging No.15 seed Lucie Safarova in a close two-setter, 7-5, 6-4.
Like Wozniacki, Williams is building herself a winning streak - she has now won six matches in a row, four coming last week en route to her 61st WTA title in Stanford and two more so far this week.
Williams leads Wozniacki in their head-to-head, 6-1. Wozniacki has pushed Williams before - she beat her in Miami two years ago, and in two of Williams' six wins Wozniacki actually won the first set, including an absolute thriller in Sydney five years ago where Wozniacki held three match points.
Wozniacki knows Williams has been gathering steam, though, and is happy for the World No.1.
"I'm not surprised. This is Serena," the Dane said. "Everyone has ups and downs in their careers, but Serena is obviously a great champion. She's an unbelievable player. You can see that with how many Grand Slams she's won, how many tournaments she's won. It's never a surprise when she's doing well.
"She's ruling the court."
Williams was asked about playing her good friend in the next round.
"It will be a great match," Williams said. "She's playing great tennis. She's really focused. She's just doing really, really well. It will be a really, really tough match.
"It will be a good match for me to see where I am.
And on running the New York City Marathon - which Wozniacki will be doing this November?
"No, no, no, no, no," she said. "Let me tell you. I think I can do a half marathon or I can run with her for the first 5K. But I am done after that. My body is clearly not made for marathon running.
"I'm a sprinter."
Another day, another win and another jog! 8km today.. Piling up the kilometers! Thanks for all the? http://t.co/iAFPUszDXX