PARIS -- The closest thing to intrigue or drama involving Rafael Nadal on Saturday came after his 31st consecutive French Open victory concluded.
That's when the eight-time champion revealed that a painful back is slowing his serves -- and, all in all, giving him more trouble than his opponents so far.
For now, leave the on-court theatrics to others. Wimbledon champion Andy Murray, for example, was clutching at aching hamstrings while being taken to 7-all in the fifth set by No. 28 Philipp Kohlschreiber before their third-round match was suspended for fading light. No. 23 Gael Monfils acknowledged tanking a set en route to a 5-7, 6-2, 6-4, 0-6, 6-2 victory over No. 14 Fabio Fognini, who was docked a point for chucking his racket near a ball boy.
"They make a good show for the crowd," Nadal said. "Long match. Crowd involved. Good for tennis."
Well, aside from the fact that Monfils and Fognini combined for more than twice as many unforced errors, 137, as winners, 66.
Nadal's play was much, much cleaner: During the entire course of his 6-2, 7-5, 6-2 win against 65th-ranked Leonardo Mayer of Argentina, the No. 1-seeded Spaniard made 10 unforced errors -- two in the first set, three in the second, five in the third.
More worrisome would be his back, which also acted up in January during a loss to Stan Wawrinka in the Australian Open final.
"During my career, I had (a) few problems. ... Hopefully will not be (the) case" the rest of the way in Paris, Nadal said.
Against Mayer, Nadal averaged only 102 mph (165 kph) on first serves, with a top speed of 114 mph.
That was down from an average of 111 mph (179 kph) and top of 122 mph in the first round last Monday.
Through two matches, Nadal faced five break points and lost serve twice. He dealt with eight break points Saturday, losing two.
The last time Nadal won 31 matches in a row in Paris, he failed to get No. 32, losing in the fourth round in 2009 to Robin Soderling -- a defeat that later was blamed, in part, on injured knees. That remains Nadal's lone setback in 63 matches at the tournament.
Next for Nadal is 83rd-ranked Dusan Lajovic of Serbia, who beat Jack Sock of the United States 6-4, 7-5, 6-3. Another American, Donald Young, lost in five sets to Guillermo Garcia-Lopez of Spain, leaving No. 10 John Isner as the last U.S. man.
Before this French Open, Lajovic had a 10-21 career record in tour-level matches, never winning two in a row.
Monfils will take on Garcia-Lopez for a quarterfinal berth. Whoever emerges from Murray-Kohlschreiber meets the winner of another suspended match scheduled to resume Sunday: No. 24 Fernando Verdasco led No. 12 Richard Gasquet 6-3, 6-2, 2-2.
Women's fourth-round matchups set up Saturday were No. 4 Simona Halep against No. 15 Sloane Stephens, 2009 champion Svetlana Kuznetsova against Lucie Safavora, 2012 runner-up Sara Errani against Jelena Jankovic, and Andrea Petkovic against 148th-ranked qualifier Kiki Bertens of the Netherlands.
In men's doubles, top seeds and former Stanford players Bob and Mike Bryan won their third-round match, beating 15th-seeded Jamie Murray-John Peers 6-3, 6-1. In the second round of women's doubles, former Cal player Raquel Kops-Jones and partner Abigail Spears (ex-UCLA), the sixth-seeded team, lost to unseeded Irina-Camelia Begu and Karin Knapp 4-6, 7-5, 7-5.