Monster Energy/Pro Circuit Kawasaki's Ryan Villopoto was fastest in both Lites seeded sessions, with his fastest being a 53.679-second lap, which actually would place him second overall among all riders in both classes.
Torco Racing Fuels Honda's Josh Grant was second fastest in the Lites class with a 54.246, which would place him sixth fastest overall.
And points leader Trey Canard was third-fastest in the Lites, just behind teammate Grant, with a 54.480-second lap.
If Villopoto wins tonight's race, he wins the championship, but if Canard wins, or if a third party wins and Canard finishes just behind Villopoto, Canard will clinch the title.
In the 450cc class, there were a few surprises.
San Manuel Yamaha's Chad Reed actually had the fastest laptime in the first practice session, but he had it removed by the AMA after he stopped for too long on the track, incurring a penalty. Still, his second-fastest time put him fourth overall after both practices, even though he sat out second practice altogether. However, it should be noted that Reed's recorded second-fastest time (after the exclusion of his true fastest time) was 1:41.620. In other words, Reed only put in two fast laps throughout the entire practice session, so his durability is still a question mark leading into tonight's race.
Reed's closest championship rival, Kevin Windham, was fastest in the 450cc class, recording a 53.356.
Honda Red Bull Racing's Andrew Short was second fastest in 450cc qualifying with a 53.814.
After his performance last week at the Moto X World Championships, where he finished third, MDK KTM's Justin Brayton jumped on a 450 for the St. Louis SX. He was eighth fastest with a 55.011, which was faster than his teammate Nick Wey.
Another Lites rider debuting on a 450 was Torco Racing Fuels Honda's Dan Reardon, who was a 450cc rider in Australia. He put in a 56.943.
And for those who still think a spring bounces you into the air in a seatbounce, here is a sequence of two photos of Nathan Ramsey:
It's easy to see that his spring never rebounds while he's on the ground, but instead waits until the load is removed (when he's in the air).
For more insight during tonight's event, tune into www.supercrossonline.com for the Supercross Live! webcast starring Jason Weigandt and Jim Holley starting at 7 p.m. Central time.