Michail Antonio scored five minutes from time to give West Ham victory over Bournemouth in the first Premier League match at the London Stadium.
Antonio rose highest at the back post to head in Gokhan Tore's cross and decide a game of few chances.
The goal came eight minutes after Bournemouth's Harry Arter was sent off for a second bookable offence.
Cherries goalkeeper Artur Boruc saved well from Enner Valencia in the first half, while Adrian denied Joshua King.
A club-record 56,977 supporters were in attendance as West Ham played their first league match at their new home, having left Upton Park at the end of last season.
As the players came on to the pitch, the traditional bubbles were blown in to the air and their club song played over the tannoy.
For the most part the home supporters were fairly quiet, though, with the vast arena meaning they are not as close to the pitch.
In fact, the noise levels were so low the travelling Bournemouth contingent chanted "is this the Emirates?" in reference to the atmosphere at Arsenal's stadium.
But having seen their team concede late in Monday's league defeat by Chelsea and Thursday's Europa League qualifying draw with Astra Giurgiu, the Hammers fans had a late goal of their own to cheer when Antonio nodded in.
Meanwhile Sunderland boss David Moyes has told fans to prepare for another relegation battle this season after his side's 2-1 defeat by Middlesbrough.
The club have lost the opening two games under Moyes, who replaced England manager Sam Allardyce this summer.
Asked about fans fearing another struggle, he said: "Well, they would probably be right.
"That's where they've been every other year for the last four years, so why would it suddenly change?"
He continued: "I think it will be, I don't think you can hide the facts, that will be the case, yes. People will be flat because they are hoping that something is going to dramatically change - it can't dramatically change, it can't."
The Black Cats' last four seasons have seen them finish 17th, 14th, 16th and 17th - often staying up thanks to late rallies. The 2010-11 campaign was the last time they did not change managers during the season.
Steve Bruce, Martin O'Neill, Paolo di Canio, Gus Poyet, Dick Advocaat and Allardyce have all been in charge in the previous five seasons.