Serena-Vika are defining friendly rivalry

Serena Williams returns a shot during her exhibition match against Victoria Azarenka. Elsa/Getty Images

NEW YORK -- After finishing their exhibition match Monday night in the BNP Paribas Showdown at Madison Square Garden, Serena Williams and Victoria Azarenka announced they are planning a collaboration. So what are the top two women tennis players in the world planning to debut?

It's karaoke. The two are planning a performance of Rihanna's raw ballad "Stay," although details are still sketchy.

"I'm studying the piano chorus," Azarenka explained at a postmatch press conference, "and she's going to sing."

That was when Williams, who won the exhibition, started to laugh. So how can fans watch this, um, duet?

"We haven't decided," Azarenka said. "We thought about maybe performing a live show, maybe in Madison Square Garden?"

They both laughed, and Williams added, "I have a lot of practice to do."

It was just a snapshot of their relationship, yet it's hard to overstate how rare it is for the top two women in the game, two women who have produced the best tennis on the tour the past six months, to be so at ease with each other when the competition is over.

"It's definitely not [usual]," said Willliams, currently ranked No. 1. "But I think we really respect each other and I like Victoria as a person. I love how she's so competitive on the court and even if she's playing me, she gets so competitive and angry and fights, but at the same time when the match is over, it's done. I like that.

"A lot of people play me, and only me, tough, but one thing I love about her -- she plays everybody tough."

Let's be honest, the 31-year-old Williams is hardly one to fake a friendship at this stage in her career. But her connection with the 23-year-old Belarusian isn't as strange as it initially may seem. The two are the most competitive and calmly confident players currently on tour, and recognize a little of each in the other.

Challenging opponent

"For us as players, it's also exciting to have someone who challenges you, who excites you to go on the court," Azarenka said. "And off the court we're doing pretty good, too."

They could relax a little more on Monday, given the fact they were playing an exhibition match. When the two meet on tour, there are championship titles and millions in prize money at stake. On Monday night at Madison Square Garden, the checks were probably already in the bank.

Rafael Nadal reportedly earned $1.5 million to make his first hard-court (kind of) event since a knee injury kept him out of competitive tennis for seven months. Williams has been dealing with a back injury, one that prompted her to pull out of a Dubai tournament on Feb. 20.

"I'm getting $3 million," Williams said wryly. "Vika's getting $3.5 [million]."

"And no taxes," Azarenka said.

It's not a bad idea: Take the best rivalry in the women's game and make it a show. Although Williams won 6-4, 6-3, the second set was more entertainment than serious tennis.

At one point, Azarenka's boyfriend, Redfoo (formerly of the group LMFAO), took over the service duties for a point. Then Azarenka served underhanded and she and Williams played a left-handed point. Fans yelled down to the players without getting a perfunctory "Quiet, please."

"That shot was sexy and I know it," yelled one fan after an Azarenka winner, referring to an LMFAO hit.

So is there any chance all this fun will sap the intensity out of their on-court rivalry? The two didn't seem concerned.

"Honestly, if I can balance it with my sister, then I can balance it with anybody," Williams said.