This being Watford, it guarantees nothing and yet Valerien Ismael, the 19th permanent manager through Gino Pozzo’s excessively lubricated revolving door, could not have made a slicker start to his life in the new job.
Ahead inside a minute, four up before half time and Ismael’s team were able to cruise through the second half preserving energies and blooding new signings.
He will not need to be told Rob Edwards started last season with a win and a clean sheet at Vicarage Road only to be sacked 10 games later, nor that Slaven Bilic lasted only five months despite winning 4-0 win in his first game, at Stoke.
Watford’s owner will demand this stylish opening game sparks a promotion challenge but for Ismael this was sweet.
For Gareth Ainsworth, it was a grim portent for the season ahead. QPR fans were jeering their team within half an hour, booing them off at half-time, and taunting the manager with chants of, “You don’t know what you’re doing” before the end.
They improved in the second half but the contest was already over, the pattern set with a goal in 34 seconds by Tom Dele-Bashiru, who burst onto a pass from Imran Louza to beat goalkeeper Asmir Begovic with a cool finish.
Louza made it two in the 20th minute, afforded all the space required to collect a short pass, turn and curl a low shot beyond Begovic from 25 yards.
Matheus Martins scored the third, a glancing header at the near post after a short corner by Louza and crossed by Ken Sema. It was a first Watford goal for Martins, a young Brazilian striker on loan from Udinese since January.
Centre-forward Vakoun Bayo converted number four, sliding and stretching to turn Francisco Sierralta’s cross into an empty net. All this in the first 43 minutes of the season. And, in truth, it could have been far worse for QPR.
Begovic made saves, the best of them to keep out a fine volley from Dele-Bashiru, hit on the run as the ball dropped over his shoulder. Bayo also went close to a second before half-time, bursting clear and lobbing the QPR goalkeeper only for his effort drop just over, onto the top of the netting.
Ainsworth made two changes at the interval and his team improved. Ilias Chair, having spent the first half marooned on the left, moved to a more central position, became slightly more influential and forced a save from Daniel Bachmann.
Substitute Sinclair Armstrong made a nuisance of himself but Watford were cruising by now and were still a huge threat. Louza, the best player on the pitch, hit the bar with another sublime curling effort before an early finish on 65 minutes.