The Danes delivered a stylish performance on Saturday when they came back from a goal down to secure victory after losing their opening Group E match to Netherlands.
"It was a highly entertaining game and possibly a performance that many of us thought they didn't have in them," Molby told Reuters.
"Going 1-0 behind, I think that helped us in many ways because then we had to come out and what we have is a bit of pace and we are good on the counter-attack. I thought it was a great game," said the ex-Liverpool player.
Denmark's win has kept their destiny in their own hands but they must beat Japan, who also have three points and a better goal difference, in their final group game on Thursday to reach the second round and maintain their World Cup record.
Critics have suggested Denmark's team lacks youth and is too reliant on players who are over 30 but Molby said the maturity of the squad had helped against Cameroon.
"We say it as well - sometimes you think, 'Well their time is up', but if they keep delivering performances like this then they probably have a few years left in them," he said.
MORE EXPERIENCED
"They have good international experience which counts for a lot. Some of them have been to three or four major tournaments and I think that showed.
"As much as they (Cameroon) had lots of enthusiasm and raw talent we just looked a little bit more experienced," he added..
"They play at a different pace but we're very good at taking the sting out of things. We took our chances when we created them - both teams could have scored more than they did."
Winger Dennis Rommedahl, 31, was the key man for Denmark, delivering a pinpoint cross for Nicklas Bendtner's first half equaliser and then producing a fine solo finish for the winner.
"He had a particularly good night," said Molby, "We know what he is capable of. He did ever so well for the first goal and the second goal, you thought if he could get inside his man the goal was on but he still had to get it right and he did."
Denmark have reached the World Cup finals on three previous occasions and have made it out of the group stage every time - including their run to the quarter-finals in 1998.
Molby expects Morten Olsen's side to reach the last 16.
"We've got Japan now and hopefully that should be OK and then it's knockout stages again," he said.
