Match ends, Korea Republic 1, Mexico 2.
Javier Hernandez scored his 50th international goal to help Mexico take a big step towards the last 16 of the World Cup with an impressive win over South Korea, despite Son Heung-min's stunning late strike.
Having upset defending champions Germany in their opening game in Group F, Mexico proved again they will be a test for any side should they reach the knockout stages.
They took the lead in Rostov-on-Don through Carlos Vela's penalty - the 14th of the tournament already - on 26 minutes after Jang Hyun-soo's handball.
Although they dominated possession against lacklustre opponents, Mexico also displayed their thrilling counter-attacking game with their second goal, when West Ham striker Hernandez added a neat finish to Hirving Lozano's surging run.
As South Korea's sole threat, it was fitting that Tottenham striker Son gave his side fleeting hope in added time with a sublime, curling strike from 25 yards.
Toni Kroos' last-minute winner for Germany against Sweden later on Saturday means Mexico need a point against Sweden in their final group match to guarantee progress.
It also prevented South Korea being eliminated, although they need to beat Germany and for Mexico to beat Sweden to stand a chance of qualification.
Can Mexico end last-16 exit streak?
While not quite guaranteed of progress, this would be the seventh straight World Cup in which Mexico have reached the last 16, a record that stretches back to 1994.
However, they have not gone further during that time, with their only two quarter-final appearances coming in the World Cups they hosted in 1970 and 1986.
This quick side, gifted on the counter but also comfortable in possession - albeit under minimal pressure here - have the chance to end that streak.
The second goal epitomised the threat of Vela, Hernandez and Lozano in attack. When the latter drove into space, Vela drew away to the right as the ball went left to Hernandez, who checked back and clipped low past South Korea keeper Cho Hyun-woo.
The defence remains a worry and the flaw that could end their run in the tournament. Centre-backs Hector Moreno and Carlos Salcedo made a series of tremendous blocks, but substitute Rafael Marquez's woeful attempted backpass nearly gifted Son a goal on 76 minutes.
Mexico could face Serbia, Switzerland or Brazil in the last 16, with the prospect of a tie against Belgium or England in the quarter-finals.
Better teams may be wise to Mexico's counter-attacking style, but no side will relish facing them on current form.
The World Cup of penalties?
Vela's penalty means more spot-kicks have now been awarded in Russia than in the entire 2014 tournament in Brazil.
This is in part due to the introduction of VAR, with six of those penalties given after video reviews, although there was no need to use that technology here.
Jang slid in on Andres Guardado and referee Milorad Mazic was well-positioned, quickly pointing to the spot when the ball struck the South Korea defender's raised arm.
After a long delay, with Cho purposefully standing off his line, Vela sent him the wrong way to make it 11 penalties converted from the total of 14.
South Korea wanted a 15th penalty - but although Moon Seon-min's shot clipped Salcedo's hand, the Mexico defender's arm was against his body and the ball struck more of his chest.
The record number of penalties in a World Cup stands at 18 in 2002. Will this tournament surpass that even before the group stages end?
Only Son shines
Following South Korea's dismal opening 1-0 defeat by Sweden, Son said it was his fault if his side did not score because he needs to "take the responsibility".
He certainly did against Mexico, attempting six of his side's eight shots in the first half - more than South Korea did as a whole against Sweden.
Perhaps that responsibility became a burden at times. He was indecisive when latching onto Marquez's backpass, failing to round Mexico keeper Guillermo Ochoa and then attempting a backheel that allowed the veteran defender to recover.
But his goal was a brilliant reminder of his talent. The 25-year-old shifted the ball onto his left foot and used a team-mate as a screen against a Mexico defender before bending a superb strike inside the far post.
Yet he could not spark a late South Korea revival.
Having shown too much deference to Sweden, the 2002 semi-finalists were less passive here but remained disjointed and over-reliant on Son.
Man of the match - Javier Hernandez (Mexico)
History for Hernandez - match stats
- Javier Hernandez scored his 50th goal for Mexico, becoming the first player in the history of the Mexican national team to reach that milestone.
- He has scored four World Cup goals, a joint record for Mexico along with Luis Hernandez.
- He is also only the third player to score at three different World Cups for Mexico (2010, 2014 and 2018) after Cuauhtemoc Blanco (1998, 2002 and 2010) and Rafael Marquez (2006, 2010 and 2014).
- Mexico have won back-to-back matches at the World Cup for the first time since winning their first two matches at the 2002 World Cup.
- South Korea have lost their last four World Cup matches, their joint-worst losing run at the World Cup -they also lost four between 1986 and 1990.
- Mexico have scored 10 penalties at the World Cup - only France, Germany and Spain have scored more in the competition's history.
Mexico face Sweden in Yekaterinburg in their final Group F game at 15:00 BST on Wednesday, with South Korea playing Germany in Kazan at the same time.
- 23Cho Hyun-Woo
- 2Lee YongBooked at 63mins
- 20Jang Hyun-Soo
- 19Kim Young-GwonBooked at 58mins
- 12Kim Min-WooSubstituted forHong Chulat 84'minutes
- 8Ju Se-JongSubstituted forLee Seung-Wooat 64'minutesBooked at 72mins
- 16Ki Sung-yueng
- 18Moon Seon-MinSubstituted forJung Woo-Youngat 77'minutesBooked at 80mins
- 17Lee Jae-Sung
- 11Hwang Hee-Chan
- 7Son Heung-Min
- 1Kim Seung-gyu
- 3Jung Seung-Hyun
- 4Oh Ban-Suk
- 5Yun Young-Sun
- 9Kim Shin-Wook
- 10Lee Seung-Woo
- 13Koo Ja-Cheol
- 14Hong Chul
- 15Jung Woo-Young
- 21Kim Jin-hyeon
- 22Ko Yo-Han
- 18GuardadoSubstituted forMárquezat 68'minutes
- 11VelaSubstituted forG dos Santosat 77'minutes
- 22LozanoSubstituted forJM Coronaat 71'minutes
- 1J Corona
- 6J dos Santos
- 10G dos Santos
- 17JM Corona
- Milorad Mazic
- Shots on Target
Second Half ends, Korea Republic 1, Mexico 2.
Chicharito (Mexico) wins a free kick on the right wing.
Foul by Hong Chul (Korea Republic).
Goal! Korea Republic 1, Mexico 2. Son Heung-Min (Korea Republic) left footed shot from outside the box to the top left corner. Assisted by Lee Jae-Sung.
Attempt missed. Héctor Herrera (Mexico) right footed shot from outside the box is too high following a set piece situation.
Héctor Herrera (Mexico) wins a free kick on the right wing.
Foul by Kim Young-Gwon (Korea Republic).
Miguel Layún (Mexico) wins a free kick in the defensive half.
Foul by Hong Chul (Korea Republic).
Attempt missed. Son Heung-Min (Korea Republic) right footed shot from outside the box is too high. Assisted by Lee Seung-Woo.
Foul by Héctor Moreno (Mexico).
Hwang Hee-Chan (Korea Republic) wins a free kick in the attacking half.
Substitution, Korea Republic. Hong Chul replaces Kim Min-Woo.
Héctor Herrera (Mexico) wins a free kick in the attacking half.
Foul by Jung Woo-Young (Korea Republic).
Attempt blocked. Lee Jae-Sung (Korea Republic) left footed shot from outside the box is blocked. Assisted by Son Heung-Min.
Jung Woo-Young (Korea Republic) is shown the yellow card for a bad foul.
Chicharito (Mexico) wins a free kick in the defensive half.
Foul by Jung Woo-Young (Korea Republic).