Qatar became the first host nation to lose an opening FIFA World Cup game when they suffered a 2-0 defeat to Ecuador on 20 November.
Former Everton striker and Ecuador skipper Enner Valencia thought he had put his side in front in just the fifth minute.
A terrible mistake by Qatar goalkeeper Saad Al Sheeb allowed Valencia to place home calmly, but VAR contentiously intervened and ruled that he was offside in the build-up.
Valencia was on the scoresheet again in the 16th minute when the Fenerbahce forward was brought down in the box by Al Sheeb, with the referee pointing to the spot.
He made no mistake as he fired his fifth FIFA World Cup goal for Ecuador, a record for any player of la Tricolor.
Valencia grabbed Ecuador's second in the 30th minute with a fabulous header from the Fenerbahce frontman.
An astute cross from Genk right-back Angelo Preciado found the Ecuador captain, who headed past Al Sheeb with aplomb.
Qatar went desperately close to scoring their first-ever FIFA World Cup goal when Al-Duhail striker Almoez Ali should have nodded home from close range in the 45+5th minute.
Ecuador were in total control throughout the first half, boasting 54% of possession.
Renato Ibarra went close in the 55th minute after Qatar defender Bassam Al-Rawi gave the ball away to Los Angeles FC's Sebas Mendez.
The Ecuadorian midfielder sent Ibarra on his way, but the forward was denied by a smart save from Al Sheeb.
Qatar struggled to conjure up any threat against Gustavo Alfaro's well-drilled team.
Brighton & Hove Albion forward Jeremy Sarmiento should have found the net in the 77th minute but sent his shot went high over the bar.
Luckily for the Ecuadorian, he was ruled offside, much to his relief.
Mohammed Muntari nearly got Qatar a goal in the 85th minute when Al Sheeb found him with a clever ball.
The Qatari striker could only fire over the bar from a long distance.
It's a first defeat for a host nation in an opening match at the FIFA World Cup and one that perhaps has people taking notice of Ecuador's talent.
Here are some reactions from supporters on Twitter to the South Americans beating the hosts at the Al Bayt Stadium:
Netherlands and Senegal face off in the second Group A encounter of the FIFA World Cup
The Netherlands and Senegal will go toe-to-toe at the Al Thumama Stadium on Monday, 21 November.
The Dutch have been in good form, unbeaten in their last 15 games across competitions.
Louis van Gaal's side boasts a squad consisting of Barcelona midfielder Frenkie de Jong and PSV Eindhoven forward Cody Gakpo, among others.
They are up against a Sadio Mane-less Senegal side who have lost two of their last five fixtures. Chelsea defender Kalidou Koulibaly skippers the side.