"It's fantastic and Roland Garros has really changed, so for us players everything has been transformed positively, it's great", said the 34-year-old who trails Nishikori 5-3 in their head-to-head record.
Nadal had suffered three consecutive semi-final defeats earlier in the clay-court season, but appeared to find his best in an Italian Open title success sealed with victory over old rival Djokovic, while his French Open win-loss record now reads 87-2.
Djokovic looked impressive throughout the match and he barely lost a point on serve and he had to play against only two break points.
He'll face another German opponent named Yannick in round two, world number 114 Yannick Maden.
Laaksonen, who has spent the a year ago battling a mysterious allergy triggered by seafood, moved into the second round with a 6-1, 6-0, 7-6 (7-4) victory over qualifier Pedro Martinez.
"It's a pleasure to play in the new court", he said.
Djokovic is bidding for his second title at Roland Garros having beaten Andy Murray in 2016 to hold all four Slams together and match Rod Laver's 1969 feat.
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"I just got nervous out there and I stopped moving my feet", Williams said. "It feels a little bit more like indoor, which I like".
"I'll know a lot about him and maybe he doesn't know as much about me", he said in an interview on the Roland Garros website.
A single break in the opening game of the match proved enough for Djokovic to take the first set, and the Serb raced through the second in under half an hour.
Later in the day, 23-time women's major champion Serena Williams takes on Russia's Vitalia Diatchenko.
The match was more or less in the bag by then, however, and Djokovic cantered to victory to set up a second-round clash with Swiss lucky loser Laaksonen.
I had to start sharp with the right intensity.
Two men's shocks saw Russian Daniil Medvedev, seeded 12th, surrender a two-set lead to lose to French doubles specialist Pierre-Hugues Herbert while Canadian Denis Shapovalov, the 20-year-old 20th seed, lost to German Jan-Lennard Struff.
Two-time Wimbledon champion, Czech contender Petra Kvitova, meanwhile withdrew ahead of her opening match, citing a forearm injury.