Tuesday's World Cup last 32 match between co-hosts Mexico and Ecuador kicked off one hour later than originally planned due to adverse weather conditions.
"Kick-off has been delayed due to adverse weather conditions. The match will begin when deemed safe," football governing body FIFA said in a first statement.
The match was to originally start at 7pm (0100 GMT) but a thunderstorm was raging above the stadium around an hour before the initial kick-off time.
In a second statement, FIFA said: "Due to adverse weather conditions in Mexico City, including risk caused by lightning in the vicinity of the stadium, the kick-off of the FIFA World Cup Round of 32 match between Mexico and Ecuador has been delayed to 20:00 local time. The safety and security of all individuals is FIFA's priority. We thank all fans for their understanding and cooperation."
In the United States, based on weather service recommendations on outdoor activities, matches are delayed or stopped for 30 minutes if lightning strikes within 13 kilometres of a stadium. Every further lightning strike sets off the 30 minute rule again.
The guidelines for matches in Mexico, however, are unclear.
The winner of Mexico v Ecuador will face either England or the Democratic Republic of Congo in the last 16.
