The Netherlands head coach, Ronald Koeman, has warned his players that “this is the level” at which they will need to perform if they want to reach the Euro 2024 final after a sparkling performance ended in a 3-0 victory against Romania.

The Oranje are back in contention after a convincing last-16 win in Munich, with Cody Gakpo scoring once and Donyell Malen twice.

Related: Donyell Malen double sinks Romania to put Netherlands in last eight

At times the superiority of the Dutch was overwhelming, just days after they appeared thoroughly disjointed in a 3-2 defeat against Austria. Koeman said his team cannot let things slip again. “The final result is always the most important thing,” he said. “But this is the level. If we go down [from this], we don’t reach the final.

“Even today the start was difficult but finally we found our positions and we scored a first great goal by Gakpo. The one critical point was that it took too long to score the second.

“Something it’s difficult to explain is why one time you play badly and one time you are sharp. Maybe it’s what happens from the beginning that makes the difference. I think we can still improve a lot, if you want to be critical after a nice afternoon.”

Koeman himself faced criticism following the Austria result and negative comparisons with the team he led that lifted the European Championship trophy in 1988. Once the captain, but now the manager, Koeman said comparisons were unjust.

“We still have great talents in the team,” he said. “You need to win something then you will be compared [positively] with 88. But it’s more difficult than that, football has changed. It’s physical, you need to be fast, you need to be technical. You saw it in all the last few [matches]; England, Portugal everybody has its own problems to continue. That means you have had good games. One of those was today, and we created a lot.”

Koeman’s opposite number, Edward Iordanescu, was full of praise for his team, while acknowledging the visible gulf in ability between the sides. But after thanking the voluminous support received from Romania’s fans, he asked that a line be drawn for his side too and that a benchmark be set for the future.

“Thank you to our boys, to our supporters, to Romanians all over the world,” Iordanescu said. “I regret we did not manage to elevate ourselves to their level. In one month in the summer you can’t compensate for 10 years. We have to get inspiration out of this and work hard. Romanian football has to have lessons; if Romanians are together they can get far, if they believe in themselves they can get far.

“We have to plan now, to develop, to grow the new generation of children. All the people who come now have to take inspiration from these boys and have them as role models because they gave everything. These are lessons you can learn but this unity that we have, this cohesion between Romanians and the national team, it could be a new beginning.”