The Netherlands defeated South Korea 4-2 on Tuesday to top their Olympic Games hockey pool with a fifth successive win which also allowed defending champions Germany to enter the semi-finals.
World champions Australia also advanced to the last four by hammering Pakistan 7-0 to move to the top of Pool A.
The other spot from this group will be decided after the match between hosts Great Britain and Spain, who were silver medallists in the 2008 Olympics.
Britain, who have eight points, need just a draw to advance, but a Spanish victory will put them in second position in the pool with 10 points.
Netherlands, assured of a semi-final spot before Tuesday's game, spiked a late rally from Asia Cup holders South Korea to complete an all-win record in the preliminary round-robin league.
The Dutch emulated their women's team, which on Monday stormed into the semi-finals by winning all five matches.
Netherlands finished with 15 points, while the defeat shattered South Korea's hopes of staying in contention. The Koreans finished on six points from five matches.
South Korea's loss meant Germany, who have nine points from four games, will finish second in the group irrespective of the result in their last pool match against New Zealand later in the day.
"We are happy, we feel strong and I have told the boys that I am proud to have 15 points," said Dutch coach Paul van Ass.
"The semi-final is a new tournament, we want to reach the final," he said.
"I am very confident with the way we are playing. The penalty corners are going very smoothly and the attack is doing well as we like it."
Young penalty corner shooter Mink van der Weerden became the tournament's top scorer with six goals when he opened the Netherlands scoring in the 17th minute with a rising flick into the top corner.
Valentin Verga fired from top of the circle in the 26th minute to make it 2-0 at half-time.
Roderick Weusthof was obstructed inside the circle and he then converted the penalty stroke in the 47th.
South Korea than came back strongly, pulling two goals back through penalty corner conversions by Nam Hyun-Woo in the 53rd minute and Lee Nam-Yong in the 62nd.
The Koreans went all out looking for an equaliser when Billy Bakker scored for the Dutch in a breakaway move that saw him shoot into an open goal in the 64th minute when goalkeeper Lee Myung-Ho was caught out of position.
Pakistan had no answer for the pace set by Australia for whom six players featured among the scorers.
Liam de Young opened the scoring with a penalty corner in the second minute, followed by a deft penalty stroke by Mark Knowles that put Australia 2-0 up in the sixth minute.
Christopher Ciriello then scored twice with a 29th minute penalty corner conversion and a field goal in the 34th as Australia seized a 4-0 lead at half-time.
The second session saw Russell Ford (42nd), Jamie Dwyer (48th) and Glenn Turner (70th) shoot on target to complete Pakistan's rout.
"We had plans to defend and counter-attack, but early goals opened up the game for us," said Australian coach Ric Charlesworth.
"The finishing needs to be clinical and crisp. It needs more work even though I'm happy with the improvement."