Valencia scored two first-half goals as Ecuador beat hosts Qatar 2-0 in the opening match of the FIFA World Cup on Sunday.
The Fenerbahce forward
Despite having 47 percent of possession, the hosts didn't manage a single shot on target while Ecuador had three.
The result marked the first time that a host team has lost the opening game of the World Cup.
The partisan crowd was sent into stunned silence when Ecuador appeared to take the lead in the fifth minute at Al Bayt Stadium in Al Khor, around 50 kilometers north of Qatari capital Doha.
Valencia powered a header into the back of the net following Felix Torres' overhead kick, but the goal was disallowed after the former West Ham and Everton forward was ruled offside by the video assistant referee.
Valencia did not have to wait long for his next chance. The 33-year-old was awarded a penalty in the 15th minute when he was tripped by goalkeeper Saad Al-Sheeb, having been played through on goal by Sebastian Mendez.
He then calmly slotted his spot-kick into the bottom right corner after sending Al-Sheeb the wrong way.
Ecuador's all-time leading scorer was in inspired form and he doubled the lead just after the half hour by straining every muscle in his neck to thump a header past Al-Sheeb following Angelo Preciado's cross.
Qatar's best chance of the opening 45 minutes came moments before the first-half whistle when Almoez Ali sent a glancing header wide of the target connecting Hassan Al-Haydos' cross from the right flank.
Ecuador emerged from the interval again looking the more dangerous team in attack. Preciado sent a speculative 25-meter shot over the bar and Al-Sheeb kept out Romario Ibarra's attempt following an errant Bassam Al-Rawi pass.
It took Qatar until the hour mark to make their first convincing attacking move of the second half. Abdelkarim Hassan sent a dangerous cross into the box from the right wing and Pedro Miguel rose highest only to see his header sail just wide.
Scoring chances for both teams were few and far between thereafter as Ecuador were content to sit back and concede possession without ever looking in danger of letting their lead slip.
Qatar will face Senegal in their next match on Friday while Ecuador are scheduled to meet the Netherlands the same day.
