The Detroit Red Wings' loss to the Chicago Blackhawks on Friday night confirmed the Ducks' post-season slot without them even taking to the ice.
But they were unable to celebrate in the fashion they would have wanted as goals from Drew Doughty and Mike Richards rendered Ryan Getzlaf's strike irrelevant.
Elsewhere in the division, the Dallas Stars beat the San Jose Sharks 2-1 thanks to Eric Nystrom and rookie Alex Chiasson.
The North-West Division's leading pair, the Vancouver Canucks and Minnesota Wild, both suffered defeats on Saturday night.
Jan Hejda's late goal earned the Colorado Avalanche a 4-3 win over the Canucks while Mark Letestu and Cam Atkinson settled a shootout in favour of the Columbus Blue Jackets, clinching a 3-2 win over the Wild.
The Calgary Flames beat the Edmonton Oilers 4-1.
In the Eastern Conference, the Boston Bruins missed out on the chance to clinch their play-off spot as they went down 4-2 to the Colorado Avalanche. Jiri Tlusty's two goals helped Colorado to only their second win in 16 games.
The Toronto Maple Leafs beat the Montreal Canadiens 5-1 to move within five points of the Bruins - the teams lie second and third in the North-East Division, behind already-qualified Montreal. Jay McClement and Phil Kessel each had a goal and an assist.
For the third time in four meetings this season, overtime was required to separate New York rivals the Rangers and the Islanders. Dan Girardi settled the match in favour of the Rangers at Nassau Coliseum.
The Buffalo Sabres beat the Philadelphia Flyers 1-0 in Saturday night's other game, Christian Ehrhoff with the goal.