The Briton qualified third and, although he dropped behind the Porsche of Pascal Wehrlein as the German manufacturer showed great pace in Mexico, he battled with polesitter Lucas di Grassi to try to secure a podium.
In that battle, Hughes was also attempting to keep fourth away from the chasing Andre Lotterer, but a yellow flag produced for team-mate Rene Rast - who had pulled over on the exit of Turn 7 after a clash with Oliver Rowland - later came to bite.
