Rafael Nadal shakes Fabio Fognini

PARIS -- For the third time in three matches at this year's French Open, Rafael Nadal hardly looked himself for a set.

Unlike in the first two rounds, Nadal won his opening set Saturday, albeit barely. The takeaway, even after another victory, was the same: The owner of a record seven titles at Roland Garros is not the dominant force he usually is at the clay-court tournament.

"If I want to have any chance," Nadal acknowledged after beating 27th-seeded Fabio Fognini of Italy 7-6 (5), 6-4, 6-4 for his 18th straight win, "I really need to play better."

Hours later, the man Nadal beat in last year's final and could meet in this year's semifinals, No. 1 Novak Djokovic, seemed vulnerable, too. Walking to his changeover chair at 4-3 in the third set of a 6-2, 6-2, 6-3 win against No. 26 Grigor Dimitrov, Djokovic stretched his right arm -- the one he's used to win six Grand Slam titles -- several times. He then was treated by a trainer, who applied ointment and gave Djokovic a massage near the shoulder.

Two games later, the match was done, Djokovic was into the fourth round, and he raised that arm in his typical victory celebration.

His mood would shift dramatically soon. When Djokovic left the court and went to the locker room, he was told that his first coach -- Jelena Gencic, who began working with little Nole when he was 6 -- had died in Belgrade, Serbia, earlier Saturday. Djokovic issued a statement through the tournament saying that he would not be able to attend a post-match news conference.

"His team kept the news secret from him until after the match," ATP spokesman Nicola Arzani said. "He just broke down. ... He was very, very, very close to her."

As they approach each other in the draw, Nadal now meets No. 13 Kei Nishikori -- the first Japanese man in the fourth round of the French Open in 75 years -- while Djokovic faces No. 16 Philipp Kohlschreiber. The other matchups on that half of the bracket after a wild Saturday in Paris: No. 12 Tommy Haas against No. 29 Mikhail Youzhny, and No. 7 Richard Gasquet against No. 9 Stanislas Wawrinka.

Haas let a record 12 match points get away from him in the fourth set, then saved one in the fifth. He eventually pulled out a 7-5, 7-6 (4), 4-6, 6-7 (10), 10-8 victory over 19th-seeded John Isner, the last American man in the field and the player best known for winning a 70-68 fifth set over Nicolas Mahut at Wimbledon three years ago.

Haas, like everyone else, associates Isner with that marathon to top all marathons.

"I was definitely hoping it wasn't going to go like in Wimbledon with him and Mahut. I was probably going to wave the white flag before that," the 12th-seeded Haas said. "That was not going to happen to me."

Haas was one point away from winning 12 times late in the fourth set Saturday, but couldn't close it out.

He was 2 for 22 on break-point chances until converting his 23rd when Isner put a volley in the net. Haas then served out the victory.

"These long matches seem to follow me," said Isner, whose last five Grand Slam appearances ended with losses in five-setters.

"In hindsight, probably would have been better to lose in straight sets," he added, "because I feel terrible right now."

He paused and, sounding like a person trying to convince himself, added: "But I'll recover."

In Nishikori's victory, his opponent, France's Benoit Paire, was assessed a point penalty for getting coached.

Asked after the Fognini match what he's pleased with about his game at the moment, Nadal replied: "Not one."

He is trying to become the first man to win eight championships at one Grand Slam tournament and is now 55-1 at Roland Garros.

But, wearing a wrap of white tape below his oft-troublesome left knee, he was as erratic as ever Saturday, with 40 unforced errors and problems converting break points. He's never lost to a player seeded as low as Fognini at any major tournament but fell behind 3-2 when broken in the first set; perhaps coincidentally, Nadal was warned for taking too much time between points in that game. Nadal broke back, but later dropped serve again to trail 6-5.

In one stretch of that set, Nadal lost 10 of 11 points that lasted at least 10 strokes, the types of exchanges he typically controls.

If Fognini had not made as many errors as he did -- a botched overhead here, a sitter into the net there -- Nadal would have been in serious trouble. The Spaniard lost the first set against 59th-ranked Daniel Brands in the first round, and the first set against 35th-ranked Martin Klizan in the second round.

Nadal managed to pull out the first set in a tiebreaker against Fognini, but only allowed a smile to crease his face -- after 2 hours, 45 minutes of sneering -- while waving to the crowd when the match was over.

"If I can calm down, I will play better," Nadal said afterward. "Otherwise, I can go back to Mallorca and go fishing."

Information from The Associated Press was used in this report.