Babel, who missed UEFA EURO 2008 with an ankle injury, scored one and created the other for Roy Makaay as the Dutch scored in the 87th minute and in injury time to demonstrate why they are one of the favourites for a medal in Beijing.
Coach Foppe de Haan said he expected Babel to start The Netherlands' next warm-up game on Saturday. "Babel and Makaay can be a very good couple," the Dutchman said, revealing it was the fist time the Liverpool man and Makaay, 33, had played together.
While praising Babel, he also reserved a special mention for the veteran. "He's a killer, but the next game I have to see if I start him because we have to be careful with Makaay," de Haan said, referring to conserving the Feyenoord man's energy ahead of Beijing in energy-sapping temperatures.
The Netherlands, with Valencia's Hedwiges Maduro pulling the strings in midfield, were marginally the better side in a tight game at Hong Kong Stadium.
But for all Maduro's probing, the Dutch looked short of movement and pace up front, where Gerald Sibon and Makaay, two of the over-age players in the under-23 squad, failed to trouble the Cameroon defence.
Unsurprisingly, coach de Haan brought on Babel for the second half for the ineffectual Sibon. And within three minutes of the restart The Netherlands might have scored, but Makaay sliced wide.
Just when it looked like ending in a draw, Babel popped up with a cool finish three minutes from time, siding the ball coolly past Joslain Mayebi in the Cameroon goal. Makaay made the game safe in injury time after being set up by Babel.
In the earlier game, Côte d'Ivoire and the USA drew a blank. In an uneventful first half, it was the Africans, looking forward to their first Olympics, who looked the more accomplished.
It took 32 minutes for either team to register a first attempt on goal, and unsurprisingly it came from the boot of Ivorian Kafoumba Coulibaly. The midfielder, who plies his trade in France and has played for the senior national side, shot straight at US keeper Brad Guzan from distance.
Both sides made changes at the break, and the US, previously insipid, suddenly appeared interested.
But it was the Africans who should have taken the lead in the 53rd minute, but captain Gervinho shot wide from close range after Salomon Kalou's free-kick rebounded off the wall.
It was all Côte d'Ivoire after that, but they failed to score from several good chances. US coach Peter Novak said it was important to get the players used to the kind of humid conditions they will face in Beijing.
"The fitness was good and my boys played well. It was the first time in conditions like that as a group together, and definitely we looked very good," Novak said.