Bellinger got the scoring started with a 2-run home run in the bottom of the fourth, his 25th home run of the season.
Blackmon almost hit for the cycle last season in May, but put on the breaks between first and second late in the ball game.
Rockies' starting pitcher Tyler Anderson managed to escape the first inning unscathed with just four pitches despite allowing two singles.
The victor of the Dodgers-Rockies game will host the first two games of the National League Division series against the East Division victor Atlanta Braves.
He may be cocky, but the 24-year-old backed it up on the field, helping the Dodgers secure their sixth straight NL West title.
The last time a Rockie hit for the cycle was Nolan Arenado on June 18, 2017 when he walked off the San Francisco Giants to finish the feat and provide one of the most memorable endings in Rockies history.
The hidden gem in Anderson's start was his ability to pitch deep into the seventh inning to preserve the Rockies bullpen for their impending challenges.
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Conclusions after the Sevilla game: " These we keep to ourselves , it's the same when we win". Los Blancos deserved the win and manager Julen Lopetegui agreed after the match.
Buehler is 7-5 with a 2.76 ERA and 0-1 with a 2.61 ERA in five starts against Colorado.
Bellinger blasted a fastball from Marquez over the right-field fence to put the Dodgers ahead 2-0.
First baseman Max Muncy followed with another two-run homer off Marquez in the fifth to help the Dodgers put the game out of reach.
The Rockies have still yet to win a division title.
The Dodgers added a run in the sixth on an RBI single by Buehler.
Colorado have made the playoffs four times since they entered Major League Baseball as an expansion team in 1993.
In Milwaukee, Jesus Aguilar hit his 35th home run of the season and drove in three runs as the Brewers roared past the Detroit Tigers 11-0. They advanced to the World Series as the National League wildcard team in 2007.