Elsewhere, Novak Djokovic got his campaign off to a winning start with a 6-3 6-4 6-2 win over Marcel Granollers of Spain.
"I wanted to start off well, engage all engines in the right way which I have done", Djokovic said.
Under watchful eye of new coach Andre Agassi, Djokovic looked his comfortable self as he begins quest to defend the title he won a year ago in fourth attempt. "That's the only thing that wasn't great for me".
He added: "I tried to get back in it, but when I was missing so many shots I was missing, seemed like an inevitable loss for me".
- The match was del Potro's first at Roland Garros since 2012, when he lost in the quarter-final to Roger Federer.
Man arrested in theft of Portland train victim's ring
Appearing in court on Wednesday, Christian shouted: "Leave this country if you hate our freedom-death to antifa". He has yet to enter a plea on charges of aggravated murder and other crimes. "I hope they all die".
No. 17-seeded Roberto Bautista Agut led the lower-seeded winners, as his draw opened up after a four-set win over Aussie John Millman.
Canadian fifth seed Milos Raonic raced through with a routine 6-3, 6-4, 6-2 victory over Steve Darcis of Belgium.
"I want to find a way to come back to the top stronger and more resilient".
Jack Sock of the USA returns the ball to Jiri Vesely of the Czech Republic during their first round match of the French Open tennis tournament at the Roland Garros stadium, Monday, May 29, 2017 in Paris.
With new coach Andre Agassi watching from the stands, the second-seeded Serb dispatched clay-court specialist Marcel Granollers 6-3, 6-4, 6-2 to reach the second round of the clay-court major on Monday. "Was not an easy opponent in the first round, obviously", Nadal said.
Irish players named in first Lions team
Central to that will be Bryn Gatland, Warren's son and the Barbarians' fly-half; but this is not a selection based on sentiment. He is one eight brothers, who played rugby, hurling and football at various levels for Portlaoise, Laois and Ireland.
"I know I played good here before". A couple of women who have been playing very well on clay play their first-round matches, too: No. 3 Simona Halep against Jana Cepelova, and No. 5 Elina Svitolina against Yaroslava Shvedova, who is best known for winning a "golden set" all 24 points at Wimbledon in 2012.
"I got two balls, one when I missed my return, and then if it was 5-3 I thought I could finish the set and perhaps I could kind of liberate myself", Paire told a news conference.
"It was a tough first match, Schiavone can be a very tricky player", the 23-year-old Spaniard said.
Kyrgios, notorious for his periodic bad temper and sulks on court, sealed his victory on his first match point.
Fourth-seed Nadal is on a semi-final collision course with defending champion Novak Djokovic, and the Serbian takes on Joao Sousa of Portugal.
Wings Of Eagles wins the Derby
He has run two fair races this year, especially his fourth at Thirsk and has solid claims of landing the best bet. O'Brien told ITV Sport after the race: "Padraig is a brilliant rider, he's world class and always has been".
Muguruza, who claimed the women's title previous year by upsetting Serena Williams in the final, plays first on Court Philippe Chatrier.