PARIS -- The French Open is famous for its capacity to serve up surprise.
A dozen years ago, a gangly 20-year-old from Brazil named Gustavo Kuerten, ranked No. 66 in the world, won the title here at Roland Garros. In 2003, Martin Verkerk, a goofy Dutch club player, made it all the way to the final. A year later, Gaston Gaudio, ranked No. 44, won all seven of his matches.
On Friday, the brilliant men's semifinals both went the distance for the first time here since 1970 and produced two more unlikely finalists. The first was a previously under-the-radar Swede, Robin Soderling, who vaulted into the global consciousness when he took down four-time defending champion Rafael Nadal a week ago in the fourth round.
The second match, featuring a certain 13-time Grand Slam winner, wasn't televised in the United States, but you might have heard of Soderling's upcoming opponent. Guy named Federer.
Despite Roger Federer's ignominious defeat in last year's final, when he won all of four games, reports of his Parisian demise appear to have been greatly exaggerated. On the day that Nadal, complaining of aching knees, withdrew from the grass tournament at Queen's Club, Federer played himself into his fourth straight Roland Garros final.
Trailing two sets to one, Federer was carried back into the match by the affectionate crowd surrounding Court Philippe Chatrier. And after he rallied to beat a gallant, game Juan Martin Del Potro 3-6, 7-6 (2), 2-6, 6-1, 6-4, oh, how the crowd roared.
Federer played his best in the late stages of this cool, blustery match.
"Well, this is what the best players can do," Del Potro said. "They can control those points. They have this inside of them, and they come out with the best at the crucial moments."
Thus, Federer has the best chance of his career to win the only Grand Slam that has eluded him, an unexpected opportunity to tie Pete Sampras' record of 14 major titles.
After losing to Nadal four consecutive times here, three straight in the finals, Federer said: "There are no easy Grand Slam finals. The one on the other side of the net has also won all his matches.
"Obviously it's nice to see someone else in the French Open finals. I've been there before, but I don't know if it's an advantage."
Earlier, Soderling refused yet again to come to his senses. The man who has never won a clay-court title prevailed over tremendously game Fernando Gonzalez 6-3, 7-5, 5-7, 4-6, 6-4 in a match that went 3 hours, 28 minutes.
Entering Roland Garros, Soderling's Grand Slam record was an undistinguished 15-21. In this one, he's a perfect 6-0 and looking for a lucky seven.
Del Potro had never even taken a set off Federer in 12 tries, but their recent match in Madrid was a sticky 6-3, 6-4 affair.
Playing in his first major semifinal, Del Potro looked fairly loose as he chatted amiably with chair umpire Enric Molina. Del Potro seemed downright giddy when he snapped off a backhand approach shot and watched Federer's stretching forehand flutter into the net. It was the 21st stroke in the point, and it gave Del Potro the decisive break in the fifth game of the first set.
The second set spun deliciously into a tiebreaker, which Federer took forcefully, 7-2, when Del Potro's game went, temporarily, off line.
But just when Federer seemed to have established order, he lost it again when Del Potro broke him to open the third set. It happened again with Federer serving at 2-4; Del Potro hit another backhand approach and Federer stung a forehand long.
And so Federer was in trouble for the third time in five matches. He had to win two tiebreakers against Jose Acasuso in the second round, had to dig out from an 0-2 hole against Tommy Haas in the fourth and now this, with Del Potro lacing forehands all over the place.
Federer rallied, of course, but every time he charged, Del Potro pushed right back with a big serve or a timely winner. And yet, in the fourth game of the fourth set, an opening presented itself. Federer sent a shot across the net, and Del Potro banged it long. Finally, Federer had his first break of Del Potro's serve.
It happened again a few minutes later, and after an emphatic ace down the middle, Federer evened it at two sets apiece.
Del Potro, visibly tiring, was broken for the third straight time at the top of the fifth set. At that point, it seemed over.
Nevertheless, Del Potro fought on, forcing Federer to scramble, at times, on his serve; it took a brilliant, sliding, fully stretched forehand squash shot back into the open court to consolidate a 3-1 lead.
Amazingly, Del Potro, in only the fourth five-set match of his life, came back. His leaping cross-court backhand winner made it 3-3. Then Federer broke again after Del Potro saved three break points -- but double-faulted to go down 3-4.
Three hours, 29 minutes after they began, Federer hit one last forehand winner, jumped in the air and screamed.
"It feels great coming through tough matches like this," Federer said. "It's more emotional, and it's satisfying. It's a great feeling of coming through this way, not the easy way."
"It's very difficult for me to analyze the match, for the time being, because I'm very sad," Del Potro said afterward. "I really wanted to be in that final, and now I'm going to have to watch it on TV.
"If it had been in the best of three sets, I would have won. Right now, I don't have enough words to explain what I feel. I just -- that match escaped me."
It's been a terrific fortnight here for the Swedes. Bjorn Borg, the six-time French Open champion, watched Soderling outmaneuver Gonzalez, and Daniel Berta, a 16-year-old from Helsingborg, Sweden, is in the boys' final. Oh, and Saturday is Sweden's National Day.
Soderling won the first two sets, which is just about when Gonzalez's forehand started to find the range. The Chilean came hurtling back into the match with dash and verve -- and one of the greatest mad-lib affronts to officiating in tennis history.
It is customary for players, upon inspecting the mark in the clay, to rub out the evidence with their foot when they find the ball to have been good. But on his way to drawing even, Fernandez raised his game by lowering himself over the mark -- which had, correctly, been called good by the linesperson -- and wiping the slate clean, as it were, with his, uh, behind.
None of the clever wags in the Philippe Chatrier press room had ever seen this done, and they had a wonderful time describing Gonzalez's actions. A sampling:
Cheeky. Re-buttal. Smart-ass. A not-so-classic "sitter."
But we digress.
When Gonzalez ran out to a 4-1 lead in the fifth set and Soderling double-faulted to go down 15-30, the match appeared to be over.
"No, it didn't look good," Soderling allowed. "I have to admit I was tired. But I felt like, 'OK, this is not how it's going to end. I have to try everything I can.'
"I just tried harder, and all of a sudden it all worked again."
Indeed, Soderling had one more burst in him and won 11 of the next 12 points. Ultimately, he won the last five games, moving him to drop to his knees when it was over.
So which was more gratifying -- beating Nadal or reaching a first Grand Slam final?
"It's two different matches," Soderling said. "I did what's supposed to be impossible, beating Nadal on clay. So it was great, but today it was a semifinal.
"They're both going to be matches that I will remember for the rest of my life, but in different ways."
Greg Garber is a senior writer for ESPN.com.