A brace from star striker Mario Mandzukic and goals from veteran Ivica Olic and Ivan Perisic inspired Croatia to an emphatic victory in their second Group A clash at the Arena Amazonia in Brazil on Wednesday - the first ever meeting between the two countries.
Olic made the breakthrough 10 minutes into the first half, before team-mate Perisic sealed all three points following a brilliant solo run shortly after the break.
Mandzukic added some gloss to the score line in the 60th and 73rd minutes as Croatia won their first World Cup match since 2002, having lost three and drawn two.
Niko Kovac's men have now collected three points from two games and are one point adrift of Mexico, who are level on points with host nation Brazil heading into their final group game, while Cameroon remain winless and out of contention.
Attempting to respond from their defeat to Mexico, Cameroon coach Volker Finke was forced into a change up front, with captain Samuel Eto'o ruled out due to an on-going knee injury. Defender Cedric Djeugoue also made way for Joel Matip.
Croatia made three changes to the team that lost to Brazil last week. Mandzukic returned from suspension and he was joined in the line up by Danijel Pranjic and Sammir as Nikica Jelavic, Sime Vrsaljko and Mateo Kovacic dropped out.
Cameroon settled the quickest out of the two teams, though Croatia eventually found their groove to open the scoring in the 11th minute.
Darijo Srna attempted to pick out Mandzukic inside the penalty area, only for the Cameroonian defender to get ahead of the Bayern Munich sharpshooter.
But the ball fell to Perisic, who played it across the six-yard box for Wolfsburg team-mate Olic to fire home from close range - his 19th international goal since making his debut in 2002.
Cameroon's task was made a lot tougher just five minutes before the half-time interval, when midfielder Alex Song saw red for an incident behind play.
The Barcelona player lashed out at Mandzukic, striking the forward on the back as Croatia pressed ahead on the counter attack.
It went from bad to worse for Cameroon three minutes after the break as Croatia doubled their advantage through Perisic.
The Croatian midfielder turned provider to goal scorer, driving into the area before placing the ball beyond goalkeeper Charles Itandje.
Cameroon's numerical disadvantage was evident and they almost went three goals behind following a swift counter-attacking move, however Mandzukic saw his effort go wide of the post.
Mandzukic finally got his goal on the hour-mark, rising highest to nod home Croatia's third from a corner and his 14th on the international stage.
The Croatian striker put the African nation to the sword again in the 73rd minute, tapping home an easy rebound after goalkeeper Charles Itandje's attempted save fell straight to the feet of the 28-year-old.
