Ecuador captain Enner Valencia looked to have given his nation the lead after just three minutes when heading home Felix Torres' acrobatic cross, after Qatar goalkeeper Saad Al Sheeb had flapped at Pervis Estupinan's free kick delivery.
It was a big, early setback for Qatar, who were looking to avoid becoming the first host nation to lose their opening game. The Video Assistant Referee, though, came to Qatar's rescue and ruled out the goal for offside to much confusion.
Replays did not appear to show an offside, and TV audiences were not privy to the footage the VAR team reviewed.
Eventually, VAR released the offside image which showed Michael Estrada’s right knee and shin offside in the build-up, while competing for the ball with goalkeeper Al Sheeb.
Valencia did not have to wait long to get back on the scoresheet, though, after Al Sheeb gave away a penalty and the striker duly slotted the ball home.