In the end, no-one landed the knockout blow. Mexico, so free scoring throughout the competition, concentrated more on defence, aware that at the end of the contest matters would be decided on a penalty shootout rather than points -- and they got what they deserved when they missed their first two kicks, before defending champions Brazil booked their place in the final by netting all four of theirs.
The match shaped up as a classic; a worthy chapter in a nicely brewing Latin American rivalry. Jaime Lozano's Mexico, in their 4-1-4-1 formation, threatened to swarm around the Brazil goal, but Brazil forced them back in the opening stages. The central midfield pair won the battle, Bruno Guimaraes competitive and Douglas Luiz sliding between the centre-backs, allowing both full-backs to push up and keep the Mexico wingers closer to their own goal
Just as he has done in the World Cup match between the two teams seven years ago, Mexico goalkeeper Guillermo Ochoa kept Brazil at bay, blocking a blast from left-back Guilherme Arana and tipping wide a free kick from his old adversary Daniel Alves.
But Mexico stayed in the game. They did a fine marking job on Brazil's inverted wingers, forcing the ineffective Paulinho inside onto his left foot and blunting the impact of the dangerous left-footed Antony on the right.
Brazil were clearly hampered by the absence of centre-forward Matheus Cunha, who had not recovered after pulling up with a muscular problem in the quarterfinal win against Egypt, a game where he had scored the only goal. Richarlison is the side's top scorer, but Cunha has given the attack a platform with his versatility and, especially, his back-to-goal game, an attribute that could easily see him catapulted into the senior side.
Mexico, then, were able to draw Brazil's sting and, as space opened up towards half time, they enjoyed their best spell of the game, launching swift breaks getting into the space behind Brazil's full-backs. Goalkeeper Santos was forced to show his worth, especially with a smart tip over from a Luis Romo shot as the Mexican arrived at the edge of the area to meet a cross from Uriel Antuna.
A dramatic second half appeared in prospect, but the match rarely caught fire. Mexico had one long range shot from Henry Martin, comfortably saved by Santos, and the rest of the action boiled down to whether Brazil could play their way through.
Coach Andre Jardine shuffled his pack; Arsenal's Gabriel Martinelli came on for Paulinho, clever playmaker Reinier replaced Claudinho and occasionally looked dangerous, while Malcom was introduced in extra time for Antony.
But it was the old stalwarts who came closest. Alves put in a cross from the right, and Richarlison's header was glanced almost to perfection -- it came back off the inside of the far post and ran along the face of goal -- before Reinier failed to arrive in time and the opportunity passed. And with Mexico content to run down the clock, there was an inevitability about the drift towards the shootout.
At the final whistle, Brazil's players were facing the same destiny as their women's team earlier in the week -- a shootout defeat to CONCACAF opposition, with the (scant) consolation of the chance to win a bronze medal.
But they were lucky enough to win the toss to shoot first, and went with experience. For the first kick, Ochoa got a hand to the shot from Alves, hit low to his right, but not enough to keep it out. On such margins shootouts are won.
Mexico's youngsters then failed. Eduardo Aguirre had his shot saved, before Johan Vazquez glanced the outside of the post. Gabriel Martinelli and Bruno Guimaraes netted and, at 3-0 down, Carlos Rodriguez gave El Tri some hope. but Reiner held his nerve for Brazil to book their place in a third-straight Olympic final.