Both reckon they can beat anyone if they're at the top of their game, and they believe that's right where they are heading into the season's first Grand Slam.
Williams, the defending Australian Open champion, is so focused that she hadn't even checked Saturday who her first-round opponent will be. (For the record, it's Jarmila Gajdosova, a Slovakia native who has adopted Australia as her home country.)
"I really just focus on what I need to do and what I need to do right," said Williams, seeking her ninth Grand Slam title. "If I can do it right, then I'll have positive results."
Last year, Williams came to Melbourne as a question mark, unseeded after a rash of injuries and the subject of painful questions about her weight, fitness and preparation. She still managed to win, largely on her defiant refusal to lose. She beat six seeded players along the way, including Sharapova in the final.
"I was completely under the radar," Williams said. "I had absolutely no expectations from anyone, and that really made me want to kind of prove everyone wrong."
This time, Williams won't take anyone by surprise, with her ranking back up to No. 7 and her sights set on regaining the top spot. And she clearly is in better shape, appearing in a bright red top and dripping diamond-encrusted jewelry for her pre-tournament news conference.
"It's definitely probably the fittest I've been in a while - maybe," Williams said with a smile. "My body will allow anything really. It's ready for anything. My preparation's been really good. I've been just training every day and just getting out there on the court every day.
"I don't feel any pressure at all. I feel just excited to be here. I don't feel like,
'Oh, my God, I have to win, win, win.' I just feel like I'm having so much fun every day. Obviously, I always come in thinking,
'I want to go all the way and I want to win.' I have that potential. We'll see what happens."
While she said Henin clearly deserves the No. 1 ranking, Williams claims she is more worried about the threat from her practice partner, sister Venus. Together, they ruled women's tennis before injuries piled up.
"She's playing unbelievable," Serena said of her eighth-ranked sister. "She gets every ball back."
Like the Williams sisters, Sharapova is excited about the Australian Open after a year fighting nagging injuries.