GUADALAJARA, Mexico -- Mexico took advantage of a defensive blunder by South Korea to win 1-0 on Thursday and become the first team to advance to the knockout stage of the FIFA World Cup.
It marks a major triumph for Mexico, which failed to get out of the group stage in 2022 and now has won twice on home soil in front of jubilant crowds. Mexico will also now play at least its next two games, and possibly three, in its home country.
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 and volleying into an open net.
"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."
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 on the rebound, extending his right arm to keep the ball from crossing the line.
Mexico has six points from two Group A matches, three more than South Korea and five more than the Czechia and South Africa, who drew 1-1 earlier Thursday in Atlanta. That means Mexico has clinched first in the group with a game against Czechia to spare.
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.
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 LAFC, 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. "We have one match left, today is disappointing but we shouldn't be discouraged because we will prepare well for the next match."
This time there were no empty seats in Guadalajara, contrary to what happened in the earlier match between South Korea and the Czechia. 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.
Information from The Associated Press was used in this report.