Neither of the players ran into much resistance in their quarterfinal matches Wednesday — and now both are two wins away from finishing the job.
For second-ranked Nadal, it would be a record-setting seventh French Open title, eclipsing the mark he now shares with Bjorn Borg. Nadal still hasn't lost a set in this year's tournament, after a 7-6 (4), 6-2, 6-3 victory over No. 12-seeded Nicolas Almagro in which he saved all four break points against him and improved to 50-1 lifetime on the red clay in Paris.
"I think I played one of the best matches I can play against Rafa," said Almagro, who has lost all eight matches against his fellow Spaniard. "But he's the No. 1 of the world in this surface."
Sharapova improved to 16-1 on clay this year, yet despite her recent dominance on the sport's slowest surface, the French Open is the only major tournament she has yet to win. No. 23 Kaia Kanepi was barely a speed bump on Sharapova's road to completing the career Grand Slam. The second-seeded Russian defeated Kanepi 6-2, 6-3 and will play No. 4 Petra Kvitova in Thursday's semifinals.
Kvitova defeated 142nd-ranked qualifier Yaroslava Shvedova 3-6, 6-2, 6-4. Kvitova and Sharapova will meet for the third time in the last four majors. Kvitova won their Wimbledon final; Sharapova won their Australian Open semifinal.
"When she's confident, when she's hitting the ball, she's quite dangerous, so obviously it's going to be another level," Sharapova said.
U.S. Open champion Samantha Stosur takes on first-time Grand Slam semifinalist No. 21 Sara Errani in the other women's match. Errani has had more success as a doubles player before excelling in singles this week. She and her doubles partner, Roberta Vinci, won their semifinal match Wednesday and will play for the title.
Her quest to play in the singles final goes through Stosur, whom Errani hasn't beaten in five tries. The last was a 6-3, 7-5 loss on clay in Rome.
"She's an amazing player, of course," Errani said. "She's very strong. If I'm here, it's because I'm playing good, so I want just to think about that and think to fight and make my best."
The men get a day off. On Friday, Nadal will face sixth-seeded David Ferrer, who beat Andy Murray 6-4, 6-7 (3), 6-3, 6-2 to advance to his first French Open semifinal.
Ferrer's last Grand Slam semifinal was at the 2011 Australian Open, after beating Nadal in the quarterfinals. Since that match, however, Nadal has beaten Ferrer four straight times, all on clay.
"I will try and play a beautiful match, my best tennis," Ferrer said. "I have great ambitions, and I'm quite certain this is going to be a very physical match."
While Ferrer tries to find an answer for Nadal, Murray heads back to Britain with questions about a back problem that's been bothering him this season. He said it was the clay — his worst surface — that bothered him against Ferrer, and not the back, but he was noncommital about his upcoming plans, including whether he was a sure thing to play at Queens, the key tuneup before Wimbledon.
"I'll do what's best for my preparation for Wimbledon, back or not," Murray said. "I need to get some good physical work done. That's going to be important. ... I mean, it's not a disaster if I can't play a tournament beforehand."
While Murray goes home, all three of the top men remain. In one of Friday's semifinals, No. 3 Roger Federer will face No. 1 Novak Djokovic, with Federer in search of his 17th major title and Djokovic trying to become the first man to win four consecutive major titles since Rod Laver did it 43 years ago.
Nadal is also looking to leave his mark.
Against Almagro, he faced his toughest test so far of this tournament, though that isn't saying much.
He needed 62 minutes to finish the first set, as Almagro pounded groundstrokes right back at Nadal, matching him game for game.
Almagro was up 5-4 and 30-15, but Nadal took the next three points, including a pair of 118 mph service winners.
They went to a tiebreaker, where Nadal pulled ahead 5-1, before dropping three points in a row. But Nadal answered with a cross-court backhand that forced an error and a service winner on set point that brought a yell of "Come On!"
This is what counts for drama in a Nadal match so far. Ferrer's goal on Friday is to create a little more uncertainty.
"It will be tough against him," Ferrer said, "because he's the best player on clay in history."