Co-host Mexico secured its spot in the World Cup knockout rounds as the first team to qualify by defeating South Korea 1-0 in front of an enthusiastic crowd at the Guadalajara Stadium on Thursday.
Following a dreary first period, Luis Romo capitalized on a goalkeeping error just after half-time to score the winner, securing Mexico's spot as Group A winners with a game to spare.
Mexico goalkeeper Raul Rangel preserved the lead with a superb double save in the final minutes.
By finishing top, Mexico stays home for the round of 32 to play a third-placed team in Mexico City.
"It's really difficult to deal with the emotions," coach Javier Aguirre said of the challenges going into the game.
He gave special praise to Rangel and the Guadalajara crowd. "His save was just amazing," said Aguirre.
"It was quite a tactical match, and hard to digest for the fans, but they were outstanding. I would just like to say thank you to them, they've been fantastic ever since we got here," he said.
South Korea sits second with three points, while the Czech Republic and South Africa remain in contention with one point each.
Hong Myung-bo's team faces South Africa next and remains well-positioned to advance.
Aguirre made three changes to the side that beat South Africa 2-0 a week ago to open the tournament.
Hong made just one alteration for South Korea, largely keeping faith in the team that fought back to defeat the Czech Republic 2-1.
Skipper Son Heung-min had the first sniff at goal after 15 minutes, looping the ball over Rangel only for Edson Alvarez to clear it off the line with a bicycle kick.
Los Angeles FC attacker Son was belatedly flagged for offside, although replays suggested it was a close call.
Julian Quinones, who scored the opening goal of the tournament, then forced South Korea goalkeeper Kim Seung-gyu into a good save from a header, raising the decibels.
The rest of an uneventful half belonged to South Korea as it stroked the ball around at will, without ever creating a clear chance, but the team did succeed in silencing the home support.
Jeers rang out at half-time from the Mexico fans.
The hosts started the second period with far more intent, and five minutes in, they went ahead when goalkeeper Kim came for a high ball and clattered into his own player, spilling it straight to Romo.
The midfielder just needed to tap the ball first-time into an unguarded net, triggering absolute pandemonium in the stands.
Hong surprisingly hauled off veteran talisman Son before the hour mark, replacing him with Oh Hyeon-gyu, while also introducing Wolverhampton Wanderers' Hwang Hee-chan for Lee Jae-sung.
But the Koreans remained mostly toothless going forward until the final few minutes, when Guadalajara native Rangel came to Mexico's rescue with a stunning double save.
Mexico will face the Czech Republic in their final group game, following a 1-1 draw between South Africa and the Czechs earlier in the day.