UFC Director of Canadian operations Tom Wright told MMA Fighting that within 6-7 minutes of the box office opening, more seats had been added to meet the demand, and within an hour, available tickets were down to single seats.
The number of tickets sold has already shattered the the current paid North American MMA attendance record, which was just set at UFC 124 in Montreal, when 23,152 filled the Bell Centre.
"Sales were terrific, is the easiest way to say it," Wright told MMA Fighting. "As you might know, it took a long time to properly setup and scale Rogers Centre for UFC 129. This is our first time out of hockey and basketball venues and into a baseball and football stadium. We took great pains to make sure it's a great experience for fans."
Wright said there will be a limited number of tickets left for Friday's pre-sale and for Saturday's general public sale.
He added that more seats would be added to try to accommodate as many fans as possible without compromising the live event experience, saying that 50,000 fans seemed "a tall order" given the stadium configuration.
Wright noted that UFC 129 will feature 14 screens, two "Fan Zones" and bleachers that will take up space and kill other seats.
The event is also likely to shatter the North American MMA gate record, but Wright could not yet confirm that, saying, "We hope to have that information as early as this weekend, but I like our chances." Adding more juice to the record-smashing weekend will be the UFC Fan Expo, which could draw as many as 100,000 people, according to Wright.
The show's main event features UFC welterweight champion Georges St. Pierre defending his belt against No. 1 contender Jake Shields.