Each have earned career-high rankings this year despite a fire and ice on-court contrast. Gavrilova's boundless energy and big cuts at the ball have earned her wins over Petra Kvitova and Simona Halep. Kasatkina's steadier rise and smoother swings helped her begin the season by beating Venus Williams and Timea Bacsinszky.
Off the court, the pair are completely in-sync, finishing each others sentences and joking about everything from their first meeting on the singles court at last year's US Open to their decision to play doubles this summer.
Celebrate the one-year friendaversary of "The Dashas" - or Dasha and DashKa - courtesy of a chat with WTA Insider, held after their first round win over Gabriela Dabrowski and María José Martínez Sánchez:
On how they met?
GAVRILOVA: Well, I was meant to play Maria Sharapova...
KASATKINA: It's a nice story! I got lucky loser.
GAVRILOVA: She got a lucky loser, and I only found out two hours before I was going to bed, and I was like, 'Who is this girl?' I had no idea.
KASATKINA: I knew her for a lot of years, and she didn't remember.
GAVRILOVA: She was telling me that she and her brother both knew me.
KASATKINA: Short memory; it's ok, Dasha!
GAVRILOVA: They were watching me when I was younger.
KASATKINA: Oh yes, we were big fans!
GAVRILOVA: After the French Open this year, we decided to play doubles together.
KASATKINA: No! I think at the end of the year, we'd already started talking about it?
GAVRILOVA: But at the time, I was set with Svitolina and she was playing with Vesnina. So we were thinking, 'What are we going to do?'
KASATKINA: We started at Wimbledon.
GAVRILOVA: We did all right there.
KASATKINA: We did two rounds!
On becoming friends?
GAVRILOVA: First, we said hello to each other last year. After I lost to her, I came up and said, 'Hey Dasha, good luck tomorrow!' But she was so scared of me. She was shy.
KASATKINA: Because after the match, you went off the court and you started to scream at your coach.
GAVRILOVA: She was 18 and super new on tour. She was scared of everything...
KASATKINA: ...And she was so experienced already.
GAVRILOVA: Our match was a big battle, and I had a few tough calls there.
KASATKINA: It was such big motivation for me; I had to take my chances.
GAVRILOVA: But I went up to her after the match because I'm kind of normal, I guess.
KASATKINA: And I was still under pressure, saying, 'Thank you.'
GAVRILOVA: Now we practice more together with the doubles and stuff. But Montréal was our first singles practice. In Indian Wells, we still didn't really know each other much. I don't know when we started hanging out.
KASATKINA: I'm not sure either. Little by little.
On whether they talk tennis?
KASATKINA: This year, I asked her what it's like to defend points, because of Rome.
GAVRILOVA: I did all right there.
KASATKINA: You made it pretty good.
GAVRILOVA: But her coach is experienced, so he gives good advice.
KASATKINA: My coach, he is. He is.
On doubles strategy?
GAVRILOVA: Well, we know we're good from the baseline?
KASATKINA: You mean good from behind?
GAVRILOVA: And at Wimbledon, it really works, you know, to just grind on the grass.
KASATKINA: Yeah, it really works. Spin the ball, kick serve.
GAVRILOVA: We probably do a lot more of standing across from each other at the baseline, more than other doubles teams.
KASATKINA: But now we're starting to play more of a doubles game. More normal.
On beating doubles specialists in their first round?
GAVRILOVA: I'd played them at the French Open with Elina, so I kind of knew what to expect. Our coaches studied them a little bit. We knew what was coming, so we played to our strengths. Yesterday we practiced for two hours?
KASATKINA: Only doubles.
GAVRILOVA: We didn't really have a chance to practice doubles. Before Montréal, we got a wildcard and didn't have to do anything.
KASATKINA: Montréal? Cincinnati!
GAVRILOVA: Oh, Cincinnati, yeah.
KASATKINA: Before the Olympics, we didn't play doubles because of that. So I played with a Russian player. Dasha had to play with Australian player.
GAVRILOVA: So in our first match Cincinnati, we didn't know what was happening, or what to do.
KASATKINA: We played not so good.
GAVRILOVA: But now that we're doing some doubles training, we'll get our stuff together.
Dasha squared... love them! pic.twitter.com/T3BYQXXYp0
? James Peeling (@Moo_Tennis) September 1, 2016
On doubles helping singles?
GAVRILOVA: Well, after losing in the first round, we were really excited to be playing doubles!
KASATKINA: Hey, our singles matches were very good!
GAVRILOVA: No, we saw each other in the locker room. I think I finished just before her?
KASATKINA: I came into the changing room, and she was sitting, talking on the phone. I looked at her; she looked at me.
GAVRILOVA: We just gave each other a big hug.
KASATKINA: And time stops!
GAVRILOVA: We hugged for like 10 minutes, sitting there like, 'Oh, man?'
KASATKINA: It was so bad, asking each other what happened in our matches.
GAVRILOVA: We were complaining like, 'I worked so hard,' and she was saying, 'I did too.' We didn't talk about doubles though.
KASATKINA: We forgot about doubles.
GAVRILOVA: But we had dinner together - actually, she'd already had dinner, but we hung out after for a little bit.
KASATKINA: We had a little lemonade!
GAVRILOVA: We ordered lemonade, asking like, 'There is no alcohol, right?' So we had to have two lemonades.
KASATKINA: The lady comes and asks us what we want to drink; they had Sprite, and the lemonade.
GAVRILOVA: She told us it was French, and I was like, 'It's not champagne, right?' They said no, and we were like, 'Great!'