PARIS -- Samantha Stosur works through her service games briskly, as if she's got a plane to catch, or at least an early dinner reservation. Perhaps she's making up for lost time.
Stosur was developing into the WTA's best double-duty player, rising in both the singles and doubles rankings, when injury and illness cost her the better part of a year that bridged the 2007 and '08 seasons. She returned with the sense that time was fleeting and best expended on her singles game, focus that only sharpened her briefcase mentality. "She's all business," said ESPN analyst Darren Cahill. "She's got a very professional personality." Her coach, Australian Fed Cup captain David Taylor, likes to say that she's the opposite of a drama queen. Yet drama occasionally finds Stosur.
Monday, the anti-diva pulled off the theatrical feat of stopping Justine Henin's 24-match unbeaten streak at Roland Garros. Stosur kept her head when Henin won the first set, kept her alert blue eyes on the ball, and quietly took note when Henin tossed her racket in a fit of pique. Her body language never betrayed a hint of doubt, and why would it? While Henin is one of the best clay-court players in history, Stosur is the most consistent player on the surface at the moment, and she has now spent a full year in the top 20.
Since the start of her run to the semifinals in last year's French Open, Stosur is 23-3 on clay with a title in Charleston and a runner-up finish to Henin in Stuttgart. Her recent prowess has not gone unnoticed by her next opponent, world No. 1 Serena Williams. After dispatching Israel's Shahar Peer in the round of 16, Williams called Stosur "a wonderful clay-court player" who deserves to be considered one of the tournament favorites.
"I guess a lot of people have changed their idea about what kind of tennis player I am recently," Stosur observed in her usual mild tones. "I guess that's a good thing. I maybe started to live up to that potential that everyone saw when I was younger. Probably none more so than myself."
Taylor said that inner certainty is what has translated into outward results, along with a lethal kick serve that Stosur is using more judiciously and less predictably these days.
"Coming into Roland Garros in 2009, she had one win and two losses on clay," he said. "I think the big difference is her conviction to do what's correct tactically in a big moment. She doesn't let emotion get in the way as much. She knows she has to hit a certain spot and she does everything she can to hit that spot instead of maybe playing passively or wanting the other girl to lose the point.
"I think Sam learned a lot [in Stuttgart], and I think maybe she believed she could win today, and that was the difference. A lot of people had been talking the match up, saying Sam can win, but it doesn't mean anything unless she believes she can win."
Will she display that kind of serenity against Serena? The match will showcase two of the best serves in the women's game, although Stosur's high kick won't bother Williams as much as it perturbed Henin because of Williams' height and two-handed backhand. Williams has followed her accustomed pattern of getting stronger as the draw gets smaller (with the exception of a brief dizzy spell against Russia's Anastasia Pavlyuchenkova that lasted all of one set). The 12-time Slam winner has the edge in movement and will try to exploit Stosur's backhand. Still, this is the major where Stosur probably has the best chance of upending Williams. "Serena rushes her on hard courts -- Stosur will have more time to set up her forehand," said ESPN analyst Mary Carillo.
Williams and Stosur have played four times, but never on clay. Stosur's only win was a three-setter last summer at Stanford; Williams steamrolled her in their next meeting, at the Australian Open. "It's important when you're playing a local girl to not let the crowd get too involved or they'll kill you," Williams said afterward, although she also lavished praise on Stosur's serve. Stosur, meanwhile, reiterated the obvious: "Playing Serena at a Grand Slam compared to a tour event is a different story."
Which of these women -- the only two non-Europeans left in the draw -- will be more at home on center court? Williams has positioned herself as a local here, reminding people that she owns a flat on the Left Bank and speaking a few French phrases in postmatch interviews. But Stosur has shown she has no problem breaking and entering, having already gate-crashed the quarterfinal matchup everyone took for granted.
Bonnie D. Ford covers tennis and Olympic sports for ESPN.com. She can be reached at email@example.com.