NEW YORK -- The U.S. Open is known especially for its fantastic upsets, but if the tennis world was looking at Sunday’s match between Serena Williams and 15th-ranked Sloane Stephens to mark one step closer to the proverbial changing of the guard in American women’s tennis, the top seed had other plans.

The hype around the two coming into the matchup has been building since Stephens slammed Williams in an ESPN The Magazine article in May. "She's not said one word to me, not spoken to me, not said hi, not looked my way, not been in the same room with me since I played her in Australia," Stephens told ESPN. "And that should tell everyone something, how she went from saying all these nice things about me to unfollowing me on Twitter.

"Like, seriously. People should know,” Stephens continued. "They think she's so friendly and she's so this and she’s so that -- no, that's not reality! You don’t unfollow someone on Twitter, delete them off of BlackBerry Messenger. I mean, what for? Why?"

Williams, in response, pointed out that she couldn't possibly be a mentor for someone she was still playing against. After all, Stephens topped her earlier this year in the Australian Open.

In the days leading up to the match, the two tried to downplay the friction. In a pre-match preview posted on the U.S. Open's official website, the two were perfectly complimentary of each other, noting that one was a champion one many times over and the other always came up big in big tournaments. But the budding rivalry between the two American women drew a packed house and the height of the chatter at Sunday’s Open.

"It definitely feels like something big, because [Stephens] is such a good opponent," Williams said after winning 6-4, 6-1, when asked about the attention. "How excited are we about the future of American tennis right?"

On the court, Stephens stayed with Williams for the first set, which took four trips to deuce and three set points, before Williams won 6-4 by capitalizing on small miscalculations of Stephens. Stephens held her own, battling back when it looked like Williams was ready to run away with it, using her incredible power (she was hitting serves that reportedly sped at 119 mph). The second set also started with a battle, but once Williams struck out to a 4-1 lead and changed the momentum from back and forth to one going her way, she never looked back.

With Stephens down 5-1 in the second set, she began to show her first signs of outward frustration. "Hopefully," John McEnroe commented on CBS as the crew began announcing the next time Williams would be taking the court, “Sloan learns something," as it was clear the match was over.

One hour and 28 minutes after the two took the court came the midcourt handshake and some quick polite words where Stephens seemed to have a smile all but frozen on for the TV cameras.

"I mean, obviously, she's No. 1in the world for a reason," Stephens told reporters afterwards. "I thought she played really well herself. Obviously it didn't go how I wanted. The second set got away from me for a little bit. All in all I thought I competed well. That's all you can do really."

While the match didn’t quite represent a handover (or for those who saw Williams' power anything close to it) in American tennis, it did represent what is quickly becoming another exciting age for women's tennis in America: An exciting 20-year-old who is incredibly likable and also is apt to get in trouble with what she calls her naivete at times (we’ll call it being 20 and having a microphone in front of you to air your grievances). A 31-year-old who seems to be still at the top of her game. And an audience that is more than willing to pay attention to a budding rivalry.

And though Stephens may have not quite played up to Williams' level in this tournament, she said she still is embracing the idea of being anointed the heir apparent to her reign in American tennis, though not taking anything for granted. This year, she hopes to make it into the top 10 (she's about 200 points away) and continue to work on her game.

"I think it's tough because there's a lot us," she said, of the idea that she is the next great American star. "I think just because I'm top 20 now there could be three other American girls in the top 20. It just depends.

"Right now I'm carrying the little torch," she added. "But I'm OK with it. I embrace it for now."