Fans returned to Mexico City's Azteca Stadium for its long-awaited reopening on Saturday, embracing the pre-World Cup atmosphere despite tight security, protests across the capital and a fatal accident inside the venue.

Supporters streamed into the revamped venue for the first time in nearly two years for Mexico's friendly against Portugal, hoping to get a taste of the kind of atmosphere which will envelop the country during soccer's global showpiece.

Mexico will co-host the World Cup with the United States and Canada, and are set to open the tournament against South Africa at the stadium on June 11.

"We came from Puebla and we're really excited to see the stadium and start feeling that World Cup atmosphere," said Mexican fan Mariluly Cuesta, adding that the experience had been very well organised despite the heavier security presence.

Road closures and a large security operation made for a long walk to reach the gates, but many said the measures were expected for an event of this scale.

"We walked about a kilometre, but it felt very safe the whole way," said Luis Camarena, a 40-year-old businessman who attended with his family. "We're just happy to be here with the kids to watch the national team."

While many had hoped to see Portugal captain Cristiano Ronaldo, his absence did little to dampen the mood.

"We would have loved to see him, especially for the children, but we came for the spectacle," Camarena added. “This way, everyone is fully behind Mexico."

Not everyone shared the celebratory mood.

Protesters staged a demonstration on a major highway near the stadium, turning it into a makeshift football pitch to highlight what they said were shortages of housing, water, transport and electricity in the area.

Inside the stadium, the festive atmosphere was overshadowed by a fatal incident shortly before kickoff, when a man died after falling from a box seat area, according to local authorities.

There were also some teething problems for the reopening, with supporters pointing to confusion over entry points, largely linked to the stadium’s recent renovations, as well as the lack of parking as areas for improvement.

"Staff weren't always clear about which gate to use, so we had to double back," said Karime Gonzalez, an 18-year-old student. "If we didn't have come with time, that could have been a problem.

"People are helping each other find their way, it feels like a rehearsal for the World Cup," added Gonzalez.