Serena Williams and Maria Sharapova have restored order on the WTA tour.
After years of paper tigers laying claim to the top of women's tennis, these ladies are justifiably battling for the year-end No. 1 ranking.
They are the two biggest names in the game.
Williams has earned more prize money than any woman in the history of sports. Sharapova has earned more endorsement money than any woman in sports. Williams has the most Twitter followers. Sharapova has more Facebook followers.
But who will finish 2013 ranked No. 1?
The answer will probably emerge before the end of summer.
Sharapova could easily over take Williams at the 2013 Madrid Open. Williams, the defending champion, has to defend 1000 points. If Sharapova wins the tournament, she is No. 1 no matter what Williams does.
But then Sharapova has to defend her title in Rome. Serena withdrew from Rome last year after winning in the quarterfinals. She could reclaim the No. 1 spot if Sharapova falters.
Sharapova must also defend her title at the French Open, where Williams literally has nothing to considering she lost in the first round of the French last year.
Winning in Madrid, Rome and at the French would require a herculean effort by Sharapova.
However, if Sharapova slips to No. 2, the tide turns in the summer when Williams must defend her titles at Wimbledon and the U.S. Open. She also won at Stanford last year.
Although those tournaments are on her favorite surfaces, Williams will be 32 in September. Maintaining peak performance at her age will be tough.
If Williams manages to win Wimbledon and the U.S. Open again, nobody will be talking about Sharapova.
That would give Williams 17 Grand Slams and turn the conversation to her and Steffi Graf.
The wild card in this two-woman race is Victoria Azarenka. Azarenka has no major titles to defend. If she puts together a string of championships she could easily slip past both of them and regain the No. 1 ranking.
If this were merely a head-to-head fight for No. 1, Williams would win hands down. She is 12-2 against Sharapova, who hasn't beaten Williams in nearly 10 years.
After losing to Williams in the final of the Sony Open, Sharapova declared that she has no doubt that one day she will beat her nemesis.
Not so sure. Williams appears to have gotten inside Sharapova's head.
The loss in Miami, Sharapova's best performance against Williams in a decade, made matters worse. It's one thing to get blown off the court. It's another to play well, go up a set and a break in the second, and still lose.
How can Sharapova feel confident about any lead she has against Williams?
Still, Williams' 2012 late season run has the points system stacked in Sharapova's favor.
So it's likely Williams will finish the year as she has in most recent years, as the best player on tour.
But Sharapova will probably finish the year ranked No. 1.
Follow Merlisa on Twitter: @merlisa