Ecuador striker Enner Valencia stole the spotlight, as he scored twice to push his country to the top of Group A.
A dramatic opening to the contest saw Valencia’s header from close range ruled out for offside by the video assistant referee, but the South Americans did break the deadlock shortly after.
Qatar’s erratic goalkeeper Saad Al Sheeb brought Valencia down in the box and the ex-West Ham forward stepped up to convert the spot-kick.
It got worse for the hosts as Valencia powered in another header before half-time to leave the Al Bayt Stadium silenced at the break.
Ecuador are now the early leaders in Group A, with Qatar propping up the table behind Senegal and Netherlands who will play their first match in the 2022 World Cup on Monday, November 21.