GUADALAJARA, Mexico (AP) — Mexico took advantage of a defensive blunder by South Korea to win 1-0 and become the first team to advance to the knockout stage of the World Cup on Thursday, June 18, sending fans onto the streets across the country to celebrate.

It marks a major triumph for a team that failed to get out of the group stage in 2022 and now has won twice on home soil in front of jubilant crowds. Mexico players celebrated at midfield and waved to the fans who cheered and sang from the packed stands at Estadio Akron.

As soon as the final whistle blew, the mariachis began to sing at the Ángel of Independence in Mexico City while thousands of people walked in from all directions. Some streets in Guadalajara were filled with drivers honking horns and fans chanting and waving Mexican flags.

Luis Romo scored in the 50th minute after South Korea goalkeeper Kim Seung-gyu collided with defender Lee Gi-hyuk and dropped the ball inside the area. Romo easily found the open net after picking up the loose ball.

The South Koreans nearly equalized in the 87th minute when Mexico goalkeeper Raúl Rangel stopped a header from close range by Cho Gue-sung, then made an even better save of Yang Hyun-jun's attempt on the rebound, extending his right arm to keep the ball from crossing the line.

“It was very quick, it was pure reaction,” Rangel said. “I couldn’t really tell you what I saw, because I remember the moment of impact with my teammate and me having the ball."

Mexico won Group A with six points in two matches, three more than South Korea and five more than the Czech Republic and South Africa, who drew 1-1 earlier Thursday in Atlanta.

The top two teams from each group move on to the knockout stage, along with the best eight third-place teams. A round of 32 is being played for the first time at the World Cup after the tournament was expanded to 48 teams.

“We’ve been doing very well,” Mexico coach Javier Aguirre said. “It wasn’t a great match, but I think that our opponent didn’t let us do too much. But we still were able to score, on that mistake, in addition to another two or three opportunities.”

Aguirre said it felt good for the players to guarantee their spot in the next round back in Mexico City.

“It relieves some of the pressure,” he said. “But not for me, for the players. They are euphoric, they are very happy.”

Mexico opened with a 2-0 win over South Africa, while South Korea rallied for a 2-1 victory over the Czechs.

Mexico closes group play on Wednesday against the Czech Republic in Mexico City, while South Korea takes on South Africa in Monterrey.

Mexico had never won a World Cup game on home soil outside Mexico City. Before 2026, all but one of its nine World Cup matches at home, spanning the 1970 and 1986 tournaments, had been played at Estadio Azteca, with five wins and three draws. When it played in Toluca in 1970, it lost 4-1 to Italy in the quarterfinals.

Thursday's match got off to a lackluster start, with neither team creating significant scoring opportunities and both squads getting loudly booed after the halftime whistle.

Mexico, ranked 13th, was eliminated in the group stage four years ago in Qatar. That followed seven straight eliminations in the round of the 16.

South Korea star Son Heung-min had another disappointing game and was substituted out in the 57th.

The 33-year-old Son is looking to become South Korea’s top goal scorer at the World Cup and the Asian player with the most goals in the tournament. The former Tottenham star, currently with Los Angeles FC, entered with three goals over three prior World Cups.

Kim kept Mexico from adding to the lead by coming up with a tough save off a close-range shot by Raúl Jiménez in the 75th.

The South Koreans pressed through the end but could not equalize.

South Korea, ranked 22nd, is making its 11th straight World Cup appearance and 12th overall, the most of any Asian country. Its best result was a fourth-place finish at the tournament it co-hosted with Japan in 2002. Since then, the South Koreans have never gone beyond the round of 16.

“The mistake that we made was unfortunate,” coach Hong Myung-bo said.

This time there were not many empty seats in Guadalajara, contrary to what happened in the earlier match between South Korea and the Czech Republic. FIFA had blamed fans standing in the concourses for the empty seats. Thursday's crowd was announced at 45,522 for the 45,664-capacity stadium, which was hosting the national team for the first time.

Fan zones across Mexico were packed ahead of the game. In the biggest one, in Mexico City’s Zócalo, chants of support for the national team, shouting “Olé!” with every pass, mingled with a homophobic chant — a one-word slur that literally means male prostitute in Spanish — that has previously led to sanctions against Mexico and could spur new punishments by FIFA.

There were peaceful protests in Guadalajara organized by the families of Mexico’s 130,000 missing people.