The 19-year-old netted just after the break to secure the 1-0 win as the Gunners produced their worst display of Unai Emery's tenure.
Rice has been a near ever-present this term for the Hammers this season, playing in 19 of their 22 Premier League games and being impressive at the base of the midfield.
He committed his long-term future to the East Londoners by signing a new contract until 2024 last month and is quickly emerging as a fans favourite.
And his display and winning strike against Arsenal will only cement his status as the darling of this West Ham side.
After such a significant moment in his career, Rice couldn't help but celebrate the occasion with his fellow supporters.
Via his Instagram account the ex-Chelsea academy player shared two videos embracing with fans, including the message: "What a buzz."
Fans in attendance are heard chanting "Irons, Irons, Irons" in a homage to the club's famous nickname.
But with Bournemouth their next opponents in the Premier League in a week, Rice made a quick exit to begin preparations for the clash.
Rice remains at the centre of a tug-of-war between England and the Republic of Ireland over his international allegiance, but Pellegrini is delighted to have him available at the London Stadium.
The ex-Manchester City said: "Declan Rice is improving in every game, maybe first of all I decided for him to be a midfielder because he can play as a centre-back too.
"After that, when he was giving solid performances in that position, we tried to help him play a little bit up.
"Today you could see he played a lot of balls in front and not back, and he has a good shot, is good technically and is good on aerial duels so I think we are seeing a complete player.
"He is just 19 years old and I’m sure in the future he will be a top, top player.”
Source: Read Full Article