The official number of fans at the MGM Grand for the weigh in was 12,200, and many more were turned away as anticipation builds for tonight's pay-per-view event.
Here is a full run down of the weights as Mayweather and Alvarez make the 152lbs limit, but Danny Garcia has to lose half a pound after he weighed a little over at the the first time of asking ahead of his clash with Lucas Matthysse.
Floyd Mayweather 150.5 vs. Saul "Canelo" Alvarez 152
(WBC/WBA super welterweight titles)
Danny Garcia 140 vs. Lucas Matthysse 140
(WBC/WBA super lightweight titles)
* Garcia weighed 140.5 on the first try, reweighed at 140.
Ishe Smith 151.5 vs. Carlos Molina 153
(IBF jr middleweight title)
Ashley Theophane 142 vs. Pablo Cesar Cano 141.5
Luis Arias 162.5 vs. James Winchester 160
Ronald Gavril 168 vs. Shujaa El Amin 168
Christopher Pearson 156 vs. Josh Williams 155
Lanell Bellows 167 vs. Jordan Moore 167
Andrew Tabiti 193 vs. Edward Smith 195.
Now the weights are in, all that's left is to sit back and enjoy the year's biggest night of boxing.
Mayweather versus Canelo can be seen live on Boxnation in the UK from 1:30am, and the main event is expected to take place in the early hours of Sunday, 15th September.
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