PARIS — So, Stan Wawrinka was asked, were you aware that in the long history of the French Open, no defending champion ever had lost in the first round?

“No,” Wawrinka replied quickly, his arms crossed, the hint of a smirk on his scruffy face. After waiting a comedic beat, he added with a chuckle: “And it’s still not the case, so it’s good.”

Sure, by then, it was easy for the 2015 champion at Roland Garros to kid around, because he barely avoided making the sort of history no athlete would embrace. Eventually warming up on a gray, chilly afternoon, and twice coming back from a set down, Wawrinka edged 59th-ranked Lukas Rosol of the Czech Republic 4-6, 6-1, 3-6, 6-3, 6-4 on Monday to sneak into the second round.

“I know that physically I’m stronger than he is, and I knew that he was going to decline a little bit,” said the No. 3-seeded Wawrinka said. “That’s exactly what happened.”

Something similar transpired several hours later, when No. 2 Andy Murray faced an even greater deficit, dropping the first two sets against 128th-ranked qualifier Radek Stepanek, who at 37 is the oldest man in the field. Their match was suspended until Tuesday because of darkness.

After the net-charging Stepanek raced to a 6-3, 6-3 lead, his legs began to falter, and Murray started to work his way back into the match.

Murray took the third set 6-0 and was up a break at 4-2 in the fourth when they stopped.

There were no bracket-busting stunners, but the surprises included 2014 U.S. Open champion Marin Cilic’s 7-6 (4), 3-6, 6-4, 6-2 loss to 166th-ranked qualifier Marco Trungelliti of Argentina. Four seeded women exited, most notably No. 7 Roberta Vinci, the Italian who ended Serena Williams’ Grand Slam bid at last year’s U.S. Open.