The second one - Antonio's 10th headed goal since the start of last season - showed Payet at his most inventive, firing in the cross with a magnificent piece of individual skill.
"We were very afraid early on, especially in defence, and this was because West Ham played very well in the beginning".
"While these isolated incidents were quickly brought under control, this behaviour has no place in football and West Ham will work tirelessly to eradicate such incidents".
That gave West Ham a two goal lead, which has subsequently been cancelled out by Watford forwards Odion Ighalo and Troy Deeney, who scored a quick couple of goals to finish the first half.
Deeney still faced the trickiest of chances, but the skipper was inch flawless as he lobbed the ball over Adrian and into the bottom right hand corner.
Payet, starting his first match of the season after recovering from a thigh problem, provided the corner for Antonio's first before delivering a stunning rabona cross for his second. And when Ighalo picked out Jose Holebas, the Greek defender fired past Adrian to extend the Hornets lead further and spark a mass exodus as well as some ugly scenes in the stands in the process.
"It was too easy for them to get in those positions".
West Ham threaten to issue life bans after trouble mars Watford clash
Watford boss Walter Mazzarri said: "We didn't start well but change of formation allowed us more possession".
"Basically, it was a very good forty minutes with so much good action".
"As a player I though they were trying to mug us off a little bit", Deeney told BBC Radio 5 live.
"If anyone was looking to score another goal it was us".
And despite a late glut of pressure from West Ham, the hosts did not manage to create a clean-cut chance as their second league appearance at London Stadium ended in defeat.
"The team recognised that from a year ago and that is why it is a good combination and a good story for us".
There were also issues keeping the two sets of supporters apart as the Hornets' claimed their first Premier League victory of the season in a 4-2 win.