Mexico came from behind to reach the final of the Olympic Games for the first time in their history with a 3-1 victory over Japan at Wembley Stadium.
Japan had taken the lead through a glorious early strike from Yuki Otsu, but were pegged back by Marco Fabian's header just past the half-hour mark. In a closely-fought contest, Peralta produced the decisive goal with a long-range effort midway through the second half. Javier Cortes then came off the bench to put the result beyond doubt with a third goal deep into injury time
After not conceding a goal in the first four goals in the competition, Japan coach Takahashi Sekizuka will have been crestfallen that Mexico were allowed to take the lead from a critical defensive error. For Mexico, they have now scored eight of their 10 goals in the competition after the hour mark.
It had all begun very differently as Japan began the game in the ascendency. Hiroshi Kiyotake came close to an early goal with a fine effort from nearly 30 yards that had Jose Corona scrambling across goal as the ball went inches wide.
It was a strike of even greater quality that saw Japan take the lead after 12 minutes. After some neat passing and movement on the edge of area allowed Higashi to find Otsu, the midfielder took the ball out of his feet with a fine first touch before rifling the ball with the outside of his boot to take it away from Jose Corona and into the top corner of the net.
The goal allowed Japan to ease into the comfort of their short-passing game as Mexico struggled to get a foothold. But perhaps Japan were perhaps taking it too easy and soon paid the price.
After toiling for 120 minutes against Senegal just three days ago, Mexico made a slow start but began to display greater energy as the match approached the half-hour point.
Mexico gave a warning of their increased threat as talisman Giovani dos Santos struck a snap shot under pressure from the edge of the box that sailed wide of the upright when he would have been expected to hit the target.
It would not be long before Mexico got themselves back on level terms. Dos Santos whipped in an inviting corner from the left that Jorge Enriquez flicked on perfectly to allow Fabian to head home from six yards out.
Just moments later the two protagonists were at it again as Fabian laid in Dos Santos, who tried an ambitious chip over Shuichi Gonda in the Japanese goal but sent the ball well over the bar.
The attempt was to be one of Dos Santos' last involvements in the semifinal as he was withdrawn at half time, in what might have been a huge blow to Mexico's hopes.
The second-half continued to be a tight midfield battle, as both sides maintained their patient approach. Japan failed to profit from an early and rare opportunity, though, as Kensuke Nagai sliced his shot off target from the edge of the box.
It was Mexico that were showing the greater impetus in the final third and they got their rewards in the 65th minute. Uncharacteristically it was a Japanese error that led to their downfall. Oribe Peralta struck a shot straight at Gonda, but then criminally the Mexico striker was allowed to steal the ball back off defender Takahiro Ohgihara before making no mistake second-time around as he fired a fine effort into the top corner form 20 yards out.
The goal shook Japan and brought about an increase in attacking endeavor missing since early in the contest. Shielded by the excellent Enriquez and veteran Carlos Salcido, Mexico held firm and, in truth, were rarely threatened in the closing stages.
With the last few seconds of injury time ticking away Mexico put an exclamation point on their historic victory. Peralta was to the fore once again with a delightful back heel down the right flank to send substitute Javier Cortes through in the box, before firing low across Gonda to send his teammates wild with delight.