More than one million fans attended the opening 16 games at the World Cup hosted in Canada, the United States and Mexico, according to FIFA.
Concerns over the pricing of tickets in the run-up to the finals appeared to be borne out by swathes of empty seats at the match between South Korea and the Czechia in Guadalajara last Thursday, and Saturday's match between Qatar and Switzerland in Santa Clara, California.
However, FIFA says 1,028,429 fans were present at the matches up to and including Monday, with the stadiums 99.34 percent full, according to its data.
FIFA president Gianni Infantino was pictured on his Instagram with the one millionth fan, Aaron Bren.
"A huge thank you to all our passionate supporters who continue to fill the stadiums -- you have brought the most inclusive World Cup to life," Infantino wrote.
Despite the impressive attendance numbers and lack of drama inside and outside of stadiums thus far, a fans' group has warned of the "risk" posed by the lack of segregation at matches.
Football Supporters Europe executive director Ronan Evain told BBC Sport: "The absence of segregation is not normal for a tournament like this.
"What is worrying is that FIFA doesn't really know who has tickets here and there...by pushing so much for people to buy tickets and resell them.
"So the possibility -- or the risk -- to have fans from 'Team A' in the middle of the crowd of 'Team B' is stronger than ever before."
FIFA sources have pointed to the fact that country's most loyal supporters are grouped together in the ring-fenced "participant member association" (PMA) allocation.
The tournament will culminate at the final on July 19 at MetLife Stadium in East Rutherford, New Jersey.
Information from PA was used in this report.
