After Xabi Alonso converted a first-half penalty for Spain, Van Persie headed his side level 90 seconds before the break in Salvador, then netted Holland’s fourth to floor the world champions.
Bayern Munich star Arjen Robben also scored twice, while centre-back Stefan de Vrij also got on the scoresheet in the Group B rout.
The four Dutch goals came thick and fast in the second-half and the sheer number caught Manchester United’s Van Persie out as Spain suffered their heaviest defeat since 1963.
“We never stopped going, that’s what we told ourselves at half-time, just keep going,” said the 30-year-old striker.
“It could have been five, oh, yeah, it was five, but it could have been six, seven or eight goals, in my opinion.”
Louis van Gaal’s new formation clicked and Van Persie said the Dutch squad’s hard-work paid off under the future Manchester United manager.
“We have been working on this system for just a couple of weeks, but to see how it came off, we can be very proud,” said Van Persie.
“It was an incredible game, the pressure was on both sides.
“It was a setback when they scored their first goal, but we scored our equaliser at the perfect time.
“It was a great goal, but I saw Iker Casillas was in front of his goal, so it was a lobbed header.”
But Van Persie warned his Dutch team-mates about getting ahead of themselves with group matches against Australia and Chile still to come.
“This was at a World Cup against the best side in the world and when you see how much we wanted it, it’s a massive compliment to the team,” he said.
“We have to enjoy tonight, but from tomorrow, we have to focus on Australia.
“I have been here before, this is my fifth tournament and I don’t want us to be too excited, this is just one game and three points.
“We have to stick together and we have to improve.”