Aston Villa missed Jack Grealish as Watford returned to the Premier League with a fine 3-2 win.
Emiliano Buendia and Danny Ings started as the other Grealish replacement, Leon Bailey, was introduced in the second half.
But Watford carved through the Villa defence with ease at times, opening the scoring through debutant Emmanuel Dennis.
The Nigerian forward followed up his own blocked shot when played in by Ismaila Sarr, who himself made it 2-0 before half-time after Dennis returned the favour with an assist and his effort was deflected in by Tyrone Mings.
Cucho Hernandez made it three with a brilliant strike just after the hour mark, only for John McGinn to make it 3-1 minutes later.
Ings scored a penalty deep into stoppage time when Bertrand Traore was tripped by Adam Masina, but it was too late for Villa who start life without Grealish in unflattering fashion.
It was a return to full stadiums for the fans, but the visiting contingent will not have been too pleased with their first look at a post-Grealish Aston Villa, who looked lacklustre in midfield and had to wait until the 70th minute for their first shot on target.
Watford did not have to wait long for their first Premier League goal of the season, when debutant Dennis slotted the ball home in the 11th minute.
Captain Tom Cleverley had played in Sarr down the wing, but it was the Senegal international who did the work, driving down the right and getting ahead of Targett before picking out Dennis in the centre.
The 23-year-old’s first effort was blocked with cries of handball, but he made no mistake with the rebound, firing the ball under goalkeeper Emiliano Martinez.
However, just moments later, Sarr – who had been causing problems for the Villa defence all throughout the first half – wove his way down the right before shooting high and past Martinez to double the lead.
It was a frustrating opening 45 minutes for the visitors as they struggled to get forward and create space for their debutants at the top end of the pitch with Ings and Emiliano Buendia only seeing the ball sporadically.
Villa started the second half brightly, with one effort going across the face of goal and half-time substitute Jacob Ramsey firing a long-range effort over the crossbar, however their early energy did not turn into many clear-cut chances.
Smith’s side were still without a shot on target when Hernandez looked to have put the game past Villa just moments after coming on for his Premier League debut.
The 22-year-old Colombia international received the ball down the left and drove forward, opening up space before curling the ball expertly past Martinez to open his account for the season on his senior debut.
However, just three minutes later, Xisco Munoz’s hopes of ending his first game of the season with a clean sheet were over when another debutant, Leon Bailey, set up McGinn on the edge of the area, and the midfielder fired the ball into the top of the net.
Ings’ late penalty was not enough for the visitors, with just seconds remaining on the clock before the whistle blew at Vicarage Road as Watford secured a win on their return to the top flight.