They were ahead after 11 minutes when Ivica Olic tapped home at the far post, while they also found themselves a man up five minutes before the break courtesy of a mindless Alex Song elbow that earned the midfielder a red card.
Here, Sports Mole takes an in-depth look at another absorbing clash in the heat of Manaus.
On target: 2
On target: 9
Was the result fair?
Absolutely. Cameroon may have only had one shot fewer than their European counterparts, but the difference in serious attacking threat was plain to see. As in their opener against Mexico, the Indomitable Lions failed to unduly worry the opposition's defence anywhere near enough, despite finding themselves in some promising positions.
To be fair to Cameroon, the match hinged on Alex Song's red card. The first half was a fairly even affair and the Africans could have justifiably felt aggrieved at being behind at the interval. They were containing Croatia well and looked as likely to score as their opponents.
However, the second half belonged to the Croats as they dictated the tempo of the game and never really looked in danger of conceding, yet alone not winning the game. In the end they settled with four goals but, in an end-to-end finish to the match, they could have had a couple more. A thoroughly deserved victory.
Really disappointing once again. Hopes weren't particularly high for Cameroon following their insipid display against Mexico and, with talisman and star player Samuel Eto'o out through injury, it was hard to see how they would improve. At times there were signs of promise, but those were quickly extinguished.
They actually started the match on top and looked more likely to create something when Croatia broke the deadlock in the 11th minute. A short period on the back foot followed, but Cameroon soon got themselves back into the game and were a match for Croatia until Song's mindless red card.
They simply couldn't deal with Croatia having gone down to 10 men, and they were comfortably second best for the remainder of the match. Their defence looked incredibly leaky at times and, while they refused to move into damage limitation mode, they rarely threatened at the other end either. It could have been a lot different had they had 11 men on the field for the whole match, but as it was they put in a poor display. It is hard to see them getting anything out of the Brazil match.
They took a while to get going, but once they found their stride they looked very impressive. Of course, it is hard to truly assess their quality in a match that swung on a red card, allowing them to dominate proceedings, but they can only beat what is put in front of them, and they did that in style tonight.
Opposition teams may take note of how Cameroon kept Luka Modric and Ivan Rakitic quiet until the red card, which went a long way to stopping Croatia taking complete control of the game. However, Niko Kovac will be happy that others stepped up to the plate, and they look to have a number of players in their ranks who can cause problems for the opposition.
They will still need to improve if they harbour any hopes of emulating the class of 1998, which finished third in France, but there are positives to build on. The return of Mandzukic in particular made Croatia a more imposing threat in attack, and they will certainly now fancy their chances of grabbing the win over Mexico that would see them through to the last 16.
Sports Mole's man of the match
Ivan Perisic: With Modric and Rakitic struggling to make their usual impact, it was Ivan Perisic who stepped up to become Croatia's most dangerous player. He kept the team ticking over in an even first half, and provided the piece of quality required to open the scoring with a delightful pass to Olic.
He got his own name on the scoresheet after the restart with a magnificent solo effort, sprinting down the left before beating the keeper at his near post. Mandzukic is also worthy of a mention due to his brace, but Perisic was the best player on the park this evening.
Charles Itandje may have done better with a couple of the goals, while there was no shortage of dodgy defending from Cameroon throughout, but the only choice for gaffe of the game is Alex Song and his red card. With Perisic breaking clear, Mandzukic moved across to block Song's run off the ball.
Without the Croatia striker doing anything malicious, Song proceeded to elbow him in the back right in front of the referee. It was a moment of madness that quite possibly cost his side the game, as it had been an even encounter until that point but was all Croatia afterwards.
Pedro Proenca is one of Europe's top officials, and he showed that with a good display today. His biggest decision was the red card, which he could have missed as it happened off the ball. However, he was well placed to see it and made the right decision in showing Song a straight red.
Cameroon: In what is now effectively a dead rubber for Cameroon, they take on hosts Brazil on Monday.
Croatia: Croatia, meanwhile, have it all to fight for as they take on Mexico, also on Monday. Victory would send the Europeans through, while anything else would be enough for Mexico to progress.