Portugal lacked inspiration in the first half as coach Paulo Bento was forced to line up a makeshift midfield due to injuries to several players including Joao Moutinho, Nani and Silvestre Varela.
But the hosts reacted to the goal and pressed on in the second half, getting their reward five minutes before the final whistle when captain Ronaldo pounced on a corner and levelled with an easy finish.
"After so many changes to the initial squad call-up due to injuries I am satisfied with our football and the competitive rhythm displayed," Bento told Portuguese television RTP.
The packed 30,000-strong Algarve stadium, located in the popular tourist region of southern Portugal, had many holiday travellers in the stands but those rooting for the home side were made to wait.
Although Portugal reacted after going behind, and Ronaldo had a lobbed goal disallowed for offside, they lacked efficiency up front for most of the match.
"It's true we struggled a bit in the first half but, although the Netherlands dominated, there weren't that many chances. As for our second half, it was class. The goal was a reward for the effort put in," Bento said.
Portugal midfielder Ruben Micael should have levelled just before the half hour but missed a sitter and Miguel Veloso had a venomous shot saved by keeper Michel Vorm in the second half.
Dutch substitute Klaas-Jan Huntelaar also lost a one-on-one battle against Portuguese keeper Beto in the second-half which would have made it 2-0 but, in the end, it was the hosts who kept pushing forward until Ronaldo eventually equalised.
The Portuguese still top World Cup qualifying Group F after Northern Ireland shocked second-placed Russia 1-0 on Wednesday. Portugal have 14 points and the Russians remain two behind but now have only one game in hand.
(Writing by Daniel Alvarenga in Lisbon, editing by Ed Osmond and Ken Ferris)
