Portugal looked set for a late win when Cedric Soares scored with a deflected shot in the 86th minute, but Hector Moreno equalized for Mexico with a header in stoppage time.
Cristiano Ronaldo, coming off a tumultuous week off the field, had set up Ricardo Quaresma’s opening goal for Portugal, and Javier “Chicharito” Hernandez hit Mexico’s equalizer just before halftime.
The result left European champion Portugal and Gold Cup winner Mexico trailing host Russia in Group A. Russia opened the tournament with a 2-0 win over New Zealand on Saturday.
Soares’ goal had to be confirmed by video review but it eventually stood.
Portugal had a first-half goal by Nani disallowed after a video review, when the game was still scoreless.
“In the end it was a well-deserved result after how we played today,” Mexico coach Juan Carlos Osorio said.
“We faced the European champions, a team that plays at a very high level, and we played equal to them. It was a great result for Mexican football.”
Mexico controlled possession and spent more time in Portugal’s area, but the Euro 2016 champions were a constant threat on the counterattack in front of 34,372 fans at the Kazan Arena.
Portugal coach Fernando Santos said it was not the performance he expected from his team.
“Mexico was better, more aggressive. We played without confidence, couldn’t connect two or three passes. It was a fair result for how the teams played.”
Ronaldo made a great run from near midfield to set up Quaresma’s 34th-minute goal.
Ronaldo carried the ball into the area but was surrounded by three defenders and he passed it to Quaresma, who was free from markers on the far side of the box. The veteran forward used one touch to clear goalkeeper Guillermo Ochoa and then easily found the open net.
“I first of all thank the fans for voting for me, but it’s not the result that we wanted. Our team practically had the match won and we conceded a goal in the final minutes. That’s football though,” Ronaldo told FIFA TV.
“The team still firmly believes in itself. We know we still have lots of opportunities, there are two games remaining and that’s why we’re calm. Now we have to think about the next match because we must win.
“If we win we’ll be close to qualifying so it’s not the time to sound the alarm.”
The FIFA Player of the Year, who had scored 11 goals in seven games coming into Sunday’s encounter, was perhaps not as influential as usual but was still named man-of-the-match.
The Real Madrid striker, whose club future has been the subject of media speculation after he was accused by Spanish prosecutors of committing tax fraud, which Ronaldo denies, set up Portugal’s opener.
His pass split the Mexican defence and gave Ricardo Quaresma a golden opportunity to open the scoring.
Ronaldo was also involved in one of the game’s biggest talking points, a ‘goal’ that was disallowed after consultation with the Video Assistant Referees. His 30-metre strike bounced off the bar and Nani hammered the ball home but the referees disallowed the effort for an offside infringement earlier in the move.
“There’s no need to set off any alarms, the team was good. It was a good result at 2-1 but that’s football. They scored in the last few minutes and now we think of the next game.
“We need to keep believing in ourselves, we know we have a great chance. There are two games to go and that’s why we’re cool, we’re at ease.”
Mexico equalized less than 10 minutes later with a close-range diving header by Chicharito after Portugal defender Raphael Guerreiro failed to clear a ball crossed into the area. Mexico midfielder Carlos Vela got to the ball near the far post and sent it to the middle of the area for Chicharito’s goal. Soares scored late with a right-foot shot from inside the area after Mexico midfielder Hector Herrera gave the ball away, and Moreno’s equalizer came with a firm header from close range after a corner kick.
Ochoa made a great diving save in the 85th to keep young Portugal forward Andre Silva from scoring with a header.
Nani’s 21st minute goal was disallowed by video assistants because a Portugal player was offside in the build up to the goal.
After a free kick taken by Ronaldo struck the wall, the ball was sent back into the area where four Portugal players were in offside positions and one of them challenged for the ball, meaning he was offside.
But the assistant did not flag for the offense. Play continued for about 10 seconds until the ball got to Nani and he scored from inside the area after a shot by Ronaldo hit the crossbar.
The referee was advised the video assistants were examining the goal and they spotted the offside player.
There were concerns that the match could be suspended after warnings from FIFA against homophobic chants by Mexican fans, but they were only heard a couple of times during the match and did not cause any disruption.