Enner Valencia scored both goals for the South American outfit in the first half, and would have had a hat-trick but for a baffling VAR decision to rule out what would have been the opening goal after only three minutes.
Qatar failed to really lay a glove on their opponents in their first-ever World Cup outing, as they entered the history books in unwanted fashion by becoming the first hosts to ever lose the opening game of a World Cup.
The hosts did not have a single shot on target throughout the 90 minutes and only had three touches inside the opposition box, although they did have two standout chances which could have made things different had they been a little more ruthless.
However, Ecuador rarely looked like giving up their two-goal advantage and never needed to get out of second gear during a drab second half.
The total of 11 shots throughout the match was the lowest in a World Cup game since 1966, but for Ecuador it was the perfect start ahead of more testing matches against Netherlands and Senegal in Group A.
HIGHLIGHTS
3rd min: Ecuador think they have a perfect start to their World Cup as Enner Valencia nods home from close range after Pervis Estupinan acrobatically put the ball across the face of goal. However, VAR intervenes are disallows the goal for an offside in the build-up, although where the offside actually occurred is not immediately apparent.
15th min: Another moment to forget for Qatari keeper Saad Al Sheeb, who was also at fault for the disallowed goal, as he brings down Valencia inside the area, leaving the referee no option but to point to the spot.
16th min: Valencia dusts himself off and coolly slots home the penalty for the opening goal of the 2022 World Cup - a record-extending 36th goal for his country and fourth at a World Cup.
31st min: Make that 37 goals for his country - Valencia thumps home a brilliant header from Angelo Preciado's cross to double Ecuador's lead as well as his own personal tally for the tournament.
45+5 min: Qatar finally fashion their first chance, and it is one Almoez Ali should be taking too as he meets a cross from the right but cannot get enough on his header right at the end of the first half.
55th min: Romario Ibarra works space to shoot, but this time Al Sheeb is equal to the effort.
62nd min: Pedro Miguel makes a late charge into the box to meet a floated cross with a commanding header, steering it a yard or so wide of the target.
86th min: Almost a special moment for the hosts as Mohammed Muntari latches on to a lofted ball forward and takes the shot early, sending a fine dipping half-volley onto the roof of the net. Some inside the stadium think it is in, but it is a near miss for Qatar.
MAN OF THE MATCH - ENNER VALENCIA
Enner Valencia had been picked out as the key man for Ecuador heading into the World Cup, and he lived up to that billing with the match-winning contributions today.
The former West Ham United forward won and scored the penalty to break the deadlock, his spot kick offering no hint of nerves despite the pressure on his shoulders, while his second goal was a brilliantly-taken header full of power - one it would have taken a Gordon Banks-esque save to keep out.
Indeed, Valencia could have had a hat-trick in the opening game had his header in the third minute been allowed to stand, but VAR chalked that one off due to a questionable offside call.
The main worry for Ecuador from this match will be that their captain appeared to pick up an injury in the first half and, while he was able to continue after that, he did have an ice pack strapped to his knee when he eventually went off.
STANDOUT MOMENT
Mohammed Muntari threatened to steal this towards the end of the match with a dipping volley which landed on the roof of the net, but as that missed it has to go to Valencia's second goal.
It is not a goal which will threaten to win the Goal of the Tournament, but it was still one of very high quality as he powered an inch-perfect header into the bottom corner from a fair distance.
The Qatari defending admittedly left a lot to be desired, but there was still a lot for Valencia to do to double Ecuador's lead.
BEST STATS
MATCH STATS
Possession: Qatar 47%-53% Ecuador
Shots: Qatar 5-6 Ecuador
Shots on target: Qatar 0-3 Ecuador
Corners: Qatar 1-3 Ecuador
Fouls: Qatar 15-15 Ecuador
LINEUPS
QATAR (5-3-2): Al Sheeb; Miguel, Al Rawi, Khoukhi, Hassan, Ahmed; Al Haydos (Waad 71'), Boudiaf, Hatem; Ali (Muntari 72'), Afif
ECUADOR (4-4-2): Galindez; Preciado, Torres, Hincapie, Estupinan; Plata, Mendez, Caicedo (Franco 90'), Ibarra (Sarmiento 68'); Valencia (Cifuentes 77'), Estrada (Rodriguez 90')