Match ends, Manchester United Women 0, Arsenal Women 1.
Arsenal needed a late strike from Danielle van de Donk to win at Manchester United, as the newly promoted hosts impressed against the defending Women's Super League champions.
England goalkeeper Mary Earps had produced several fine saves to give Casey Stoney's team hope of earning their first point as a top-flight club.
But a deflection helped the ball find Van de Donk who fired home in the closing stages, just after her Netherlands team-mate Vivianne Miedema had struck the post.
Last season's second-tier winners could have won the game themselves, with Arsenal's Austria international shot-stopper Manuela Zinsberger denying Scotland's Jane Ross when one-on-one in the second half, but the Gunners were dominant late on and eventually found a way past Earps.
United, promoted from the Championship last term at the first time of asking following the reformation of the club's senior women's side in 2018, were playing in their first home game as a WSL club and were backed by a passionate crowd of 2,530 at Leigh Sports Village.
Up against an Arsenal side who impressed in a 4-0 Champions League first-leg win away at Italian side Fiorentina on Thursday, former England centre-back Stoney's team were well organised and proved difficult for the Gunners to break down. And they also carved out good chances of their own.
England Under-21 international Ella Toone headed just wide from the hosts' best first-half chance, before England forward Beth Mead's right-wing corner skimmed the crossbar at the other end as the Gunners edged the latter parts of the opening period.
Joe Montemurro's Arsenal, who began their WSL title defence with a 2-1 home win over West Ham United on 8 September, gave England star Jordan Nobbs her first start since a serious knee injury last November, and she showed good touches even though the visitors weren't at their fluid best.
United's Lionesses keeper Earps, who signed from German club Wolfsburg in the summer, produced fine double saves on two separate occasions, thwarting Miedema just before half-time before keeping out two close-range efforts from Scotland's Kim Little after the break.
She then reacted well to deny Miedema and Little again late on, before substitute Van de Donk ensured the Gunners maintained their 100% start to the campaign.
United are without a point from their opening two games, following 7 September's 1-0 loss at local rivals Manchester City, but they have only faced last season's top two sides so far.
'Man Utd deserved something from game' - reaction
Man Utd boss Casey Stoney told BBC Sport:
"I'm gutted for the players because I don't think they deserved that. They deserved more from the game and they deserved more out of the game last week too, but it's almost a repeat, of not taking our chances.
"We've had a good chance in the first half and another good chance in the second half, and it's about fine margins. Arsenal knew they were in a game tonight.
"But [my players] gave everything today - I can't ask any more from them. I'm so proud of every single one of them. Unfortunately they haven't come away with anything and that's why I'm disappointed, because they deserved something from the game."
Arsenal boss Joe Montemurro told BBC Sport:
"A lot of teams are going to find it very, very difficult here. They're a very good side.
"Part of the art of winning games is putting the ball in the back of the net. We had opportunities to do it and didn't do it, but we did it once and that was enough.
"It was a long week but we need to make sure everyone is fresh and ready to go for the weeks to come because it's only going to get tougher and tougher. Every game [in this league] is tight."
Man Utd Women
- 10ZelemBooked at 58mins
- 9SigsworthSubstituted forHansonat 78'minutes
- 19RossSubstituted forJamesat 58'minutesBooked at 90mins
- 1ZinsbergerBooked at 90mins
- 14RoordBooked at 80minsSubstituted forQuinnat 90+3'minutes
- 8NobbsSubstituted forvan de Donkat 70'minutesBooked at 90mins
- 7van de Donk
- Abigail Byrne
- Shots on Target
Second Half ends, Manchester United Women 0, Arsenal Women 1.
Lauren James (Manchester United Women) is shown the yellow card for a bad foul.
Lisa Evans (Arsenal Women) wins a free kick in the defensive half.
Foul by Lauren James (Manchester United Women).
Daniëlle van de Donk (Arsenal Women) is shown the yellow card for a bad foul.
Foul by Daniëlle van de Donk (Arsenal Women).
Leah Galton (Manchester United Women) wins a free kick on the left wing.
Substitution, Arsenal Women. Louise Quinn replaces Jill Roord.
Manuela Zinsberger (Arsenal Women) is shown the yellow card.
Attempt missed. Kirsty Hanson (Manchester United Women) left footed shot from outside the box is just a bit too high. Assisted by Abbie McManus.
Goal! Manchester United Women 0, Arsenal Women 1. Daniëlle van de Donk (Arsenal Women) right footed shot from the centre of the box to the bottom right corner.
Attempt blocked. Kim Little (Arsenal Women) right footed shot from the right side of the box is blocked. Assisted by Daniëlle van de Donk.
Attempt blocked. Leah Williamson (Arsenal Women) left footed shot from the centre of the box is blocked.
Attempt blocked. Jennifer Beattie (Arsenal Women) header from the left side of the six yard box is blocked. Assisted by Kim Little with a cross.
Corner, Arsenal Women. Conceded by Abbie McManus.
Vivianne Miedema (Arsenal Women) hits the right post with a right footed shot from the centre of the box. Assisted by Daniëlle van de Donk.
Attempt blocked. Leonie Maier (Arsenal Women) right footed shot from outside the box is blocked.
Corner, Manchester United Women. Conceded by Katie McCabe.
Attempt missed. Vivianne Miedema (Arsenal Women) header from the centre of the box misses to the left. Assisted by Kim Little with a cross following a corner.