His goal, Ecuador's second, proved to be a winning strike.
Last summer's signing for The Hammers had an impressive start to life at Upton Park but failed to carry it on consistently throughout the season, finishing with just the five goals to his name in his debut campaign, that was marred in the second half by injury.
Now he is back to full fitness and representing his country in the Copa America in Chile.
His Ecuador side needed a win against Mexico to stand any chance of qualifying for the latter stages of the competition as a best placed third team.
They did just that. Ecuador won 2-1, with Valencia scoring the second goal of the game.
He also scored in the 3-2 defeat to Bolivia on Monday, however he will probably remember that game more for his missed penalty than his goal.
Ecuador now still have a chance of making it to the next stage of the competition. They will need Uruguay or one of Brazil, Peru or Venezuela to lose by two or more goals if they are to advance to the next stage of the competition.