Hosts France reached the Olympic men's football semi-finals for the first time in 40 years with a 1-0 win over Argentina thanks to Jean-Philippe Mateta's first-half goal in a grudge match in Bordeaux on Friday.
France will face Egypt for a place in the final and Morocco meet Spain in the other semi.
Thierry Henry's France grabbed an early lead as they sought revenge in a repeat of the last World Cup final in which Argentina beat France.
Earlier on Friday, Egypt claimed a dramatic win on penalties over Paraguay after a 1-1 draw in regular time in Marseille.
Morocco outclassed the United States at Parc des Princes with an emphatic 4-0 win, including two penalties and a strike from Paris St Germain's Achraf Hakimi, to reach their first Olympic semi-finals.
Spain beat Japan 3-0 courtesy of a Fermin Lopez double and Abel Ruiz's late effort.
Barcelona midfielder Lopez scored superb goals in the 11th and 73rd minutes, and Ruiz struck late to secure the win for La Roja who beat Japan three years ago in the Tokyo Olympics semi-finals.
Mateta opened the scoring for France after five minutes with a towering header in the six-yard box following a corner.
Argentina pushed for an equaliser, but a glaring miss by Giuliano Simeone and poor finishing denied them.
At Marseille Stadium, Paraguay went close to progress to the semi-finals for the first time since their bronze-medal run at the 2004 Games in Athens.
But Diego Gomez's 71st-minute strike from a fine Julio Enciso through ball was cancelled out two minutes from time by Ibrahim Adel's close-range header.
The game was still deadlocked after extra time and Paraguay's second attempt in the penalty shootout by Marcelo Perez was saved by Hamza Alaa and the Africans converted all their spot-kicks to advance.
DOMINANT MOROCCO
Morocco dominated the US to prevail in their first-ever Olympic knock-out match.
Backed by their passionate supporters who packed the PSG stadium, Morocco grabbed the lead in the 29th minute when Soufiane Rahimi earned them a penalty and converted for his fifth goal of the tournament.
Ilias Akhomach doubled the advantage with a tap-in after a brilliant team move before Hakimi got on the scoresheet after a fine solo run to make it 3-0 20 minutes from time.
"I felt like I was playing at home in this stadium where I play for my club, but also because our fans were very loud and were here in big numbers," 25-year-old defender Hakimi told reporters.
"Fans have been following us all tournament, I hope they can follow us all the way to the final. We want to make them proud."
Substitute Mehdi Maouhoub completed the rout with another penalty in stoppage time following a VAR review for a handball.
The U.S., playing in their first Olympic quarter-final for 24 years, were better for a short spell after the break but had only one goal attempt in the match.
"We have always aimed for gold here," forward Akhomach said. "We are going to leave everything on the pitch to achieve that."
Morocco will hope to stun Spain again with fond memories from their last clash at the World Cup in Qatar where they won on penalties in the last 16.
