The Netherlands set up a likely showdown with Argentina in the women's Olympic hockey semi-final by brushing aside Spain 2-0 in their final group match on Monday.
Champions Germany qualified as the top team from the opposite pool with four wins when they beat Japan 1-0 in their fifth and final match.
Top-ranked Netherlands, silver medallists in Athens four years ago, had qualified with a game to spare on Saturday but their fifth straight victory meant they will play the second team from the opposite group in the semi-finals by topping Pool A.
They will meet Argentina in all likelihood in Wednesday's semi-finals.
Argentina are heavy favourites to win their match against win-less New Zealand later on Monday, to go clear over Britain who finished with eight points after a goalless draw with the United States.
World's second-ranked team Argentina, who came into the competition as the team to beat after winning the Champions Trophy, should still make the semi-finals on better goal difference even in the event of a surprise defeat.
The third-ranked Germans will meet the winners of the needle contest between three-times champions Australia and Asian Games winners China later on Monday.
The Dutch went ahead in the 22nd minute when the tournament's leading scorer Maartje Paumen struck her eighth goal by converting the only penalty corner they forced in the first half.
"We played slowly in the first half because we did not want anyone to get injured but the second half we played much better," Dutch coach Marc Lammers said.
They scored again two minutes before the end through Ellen Hoog.