Adrien Simon was quickest in practice by a comfortable margin for the Mexican V-Prix, on a weekend where he looks to clinch his second World Championship.
Simon simply needs to beat his rivals - team mate Allar Kangur, Downton's Nathaniel Powers and Ocelot's Puccio Giodano - to secure the title on Sunday, and his fastest time in practice will give him great confidence he can do just that.
Tumo Kinnumen was second fastest - some two and half tenths slower - while Enrique Ruiz was third, nearly half a second off the pace. Allar Kangur was fourth quickest ahead of Puccio Giodano, but the two Downton's struggled in sixth and seventh, both seven tenths of a second off Simon's pace.
Nikolai Milkovich and the two Ingram's completed the top ten ahead of Felix Beyer and Sergio Alvarez in the Holmqvist and Phoenix respectively, while Will Hoskins was a tenth down on his team mate in thirteenth. Viktor Ostberg was the lead of the Lopez cars in fourteenth just clear of Johan Halvosen, who was eight tenths faster than new team mate Gabriele García, the Brazilian even ending up behind Felix Pérez's FIRST at the Mexican's home race.
See below for full practice classification: