Pekka Rinne made 27 saves for the Predators.
Nystrom opened the scoring at 3:40 of the second period.
Austin Watson chipped the puck over a diving Cam Fowler just outside the Anaheim blue line and then chased the puck on the right boards. Watson found Nystrom in front, where he had a tap-in for his second goal of the season.
The assist was the first of Watson’s career.
Ellis made it 2-0 at 12:47 of the second.
Just after a Nashville power play, Ribeiro slid a cross-ice pass to Ellis at the left faceoff dot, where his one-timer beat Khudobin on the short side.
Ellis returned to the Nashville lineup after missing Tuesday’s game with a lower-body injury.
Ribeiro added a goal at 17:00 of the second on a shot from the lower part of the right circle after collecting the rebound of his initial attempt, which was blocked by Fowler.
Ekholm made it 4-0 when he scored his first goal of the season at 3:03 of the third on a slap shot from the left faceoff dot.
Sekac spoiled Rinne’s shutout bid with a power-play goal at 12:15 of the third. The Ducks entered Thursday as the only team not to score a power-play goal this season.
Wilson finished the scoring with a power-play goal at 18:18 of the third.
Notes: Nashville has not allowed a first-period goal this season. … Anaheim LW Andrew Cogliano played his 300th game with the Ducks. … Anaheim won all three matchups against the Predators last season.