The Dutch lost Arjen Robben to a groin strain in the warm-up, with the Bayern Munich winger's misfortune allowing Lens into the starting XI.
And Lens did not let his opportunity pass him by, turning in a man-of-the-match display.
The PSV Eindhoven striker, winning only his sixth cap, scored twice and hit the crossbar before setting up the fourth goal for Huntelaar.
Young defender Bruno Martins Indi scored his first international goal, rendering Balasz Dszudszak's eighth-minute penalty for the hosts irrelevant in the final analysis.
"I have to highlight Jeremain Lens' performance," Van Gaal told reporters.
"He had an excellent game despite the fact he only got into the starting XI just before the match started."
Van Gaal has marked the start of his second spell in charge of Holland by giving opportunities to a host of new faces.
Feyenoord midfielder Jordy Clasie was among those to impress on Tuesday night, but the coach reserved praise for experienced pair Joris Mathijsen and Maarten Stekelenburg, both of whom have been edged out of the first team by younger players in recent times.
Stekelenburg returned to the fold on Tuesday night after Newcastle goalkeeper Tim Krul was ruled out through injury, while defender Mathijsen entered the fray after an hour when Martins Indi picked up a knock.
"Immediately after Krul could not continue I could tell Stekelenburg he would goalkeeping," said Van Gaal.
"Both he Mathijsen have behaved as professionals. Which is how it should be, but it is not always."
Van Gaal added that his move towards younger players represented a risk, but was delighted that so far it had paid off with two wins from two in Group D.
"It's about the experience," he said.
"As a club coach you can easily take such a risk. As a national coach it is that much harder. It's a risk.
"Because if it goes wrong, then my head gets chopped off.
"But six points from two games, six goals for and one against. That's fine."