Valencia notched his first international goal in the 89th minute to deny Honduras victory after a friendly which saw both sides reduced to 10-men.
Valencia had only entered the fray as a 73rd minute substitute in the match in Houston.
His goal came after he blocked an attempted Honduras clearance and lashed in a shot from outside the area.
Earlier, Ecuador striker Jaime Ayovi had put the South Americans 1-0 up in the 15th minute.
However veteran Honduras striker Carlo Costly equalized on 63 minutes, latching onto a Jerry Palacios pass and rifling home a shot from around eight yards.
Ecuadoran 25-year-old forward Jaime Ayovi scored in the 15th minute to put the South American side ahead 1-0 at half-time.
A set-up pass from Jerry Palacios in the 63rd minute found Carlo Costly on the run directly at the goal and the 31-year-old striker blasted home from near the centre of the penalty area.
Costly netted his 30th international goal four minutes later to put Honduras 2-1 up courtesy of an indiviudal effort.
Costly took a long pass just inside the area and waited for support. Seeing no help coming, he dribbled a few steps to his left and blasted a left-footed shot into the upper left corner.
Costly played his most recent club action in August, scoring two goals for China's Guizhou Zhicheng.
Honduras received more help in the 76th minute when Ecuadoran defender Juan Carlos Paredes was sent off.
Stoke City midfielder Wilson Palacios was then sent off for Honduras after an 84th minute confrontation, setting the stage for Valencia's equaliser.