Riccardo Calafiori's header saw Arsenal edge to a 1-0 win against Manchester United in their Premier League opener, despite Ruben Amorim's side looking much-improved going forward.
The Old Trafford side had splashed out on three attacking players this summer - Matheus Cuhna, Bryan Mbeumo and Benjamin Sesko - who all made their Man Utd debuts on Super Sunday.
But the game was ultimately decided on a goalkeeping error. Altay Bayindir - deputising for the absent Andre Onana - failed to deal with Declan Rice's corner, allowing Calafiori to nod home inside 13 minutes.
Please use Chrome browser for a more accessible video player
Calafiori scores opener for Arsenal.
Riccardo Calafiori heads in Declan Rice's corner after a huge Altay Bayindir error to put Arsenal in front against Man Utd at Old Trafford
And David Raya needed to be at his best at the other end to keep out the lively Cunha and Mbeumo, who signed from Wolves and Brentford respectively.
Late in the first half, the Arsenal goalkeeper needed to make a low, one-handed save to fingertip Mbeumo's latest shot away from danger. Cuhna too had already fired some efforts his way, but were handled well by Raya.
Please use Chrome browser for a more accessible video player
David Raya keeps Arsenal in front with important stop to deny Cunha.
David Raya pushes Matheus Cunha's shot wide to keep Arsenal in front at Old Trafford in their Premier League clash
The spell of pressure began when Patrick Dorgu rattled the bottom of the post with a thunderous shot, which saved Raya's blushes, who was beaten.
Man Utd continued to probe for a deserved equaliser in the second half, as Arsenal - despite their lead - looked a touch behind their opponents as the game continued.
Please use Chrome browser for a more accessible video player
Dorgu hits the post.
Patrick Dorgu hits the post from distance as Man Utd push for an equaliser against Arsenal.
In the pick of the chances, Mbeumo nodded another effort goalwards after a deflected cross from Dorgu, but Raya was out again to make a spectacular save.
The Gunners registered zero shots on target in the second half and just four overall after the break, with only a few efforts of note after the goal. Martin Odegaard shot from range in the first half, while Declan Rice saw a free-kick deflect behind for a corner.
Please use Chrome browser for a more accessible video player
Raya denies Mbeumo as Arsenal hold on.
Arsenal goalkeeper David Raya denies Bryan Mbeumo as Man Utd search for a leveller at Old Trafford
But crucially, they came away with a vital three points, showing their experience to win a game they were not at their best in. While Man Utd were beaten, there will surely be plenty of encouragement that this season will be more successful all around than the last.
More to follow...
Story of the match in stats...
What's coming up in the Premier League?