William Gallas scored his first Arsenal goal since moving from Chelsea to help overcome Sheffield United's resistance.
Gallas has made superb start to his Arsenal career
Thierry Henry, back after injury, chipped a pass into the box, Cesc Fabregas half-controlled it and Gallas smashed the aloft ball into the corner.
Henry was involved in Arsenal's second when Phil Jagielka diverted the Frenchman's cross into his own net.
And Henry sealed Arsenal's first Premiership win at their new Emirates Stadium when he headed home late on.
But for long periods it had looked as though the visitors would be the latest team to leave Arsenal frustrated at their new home.
And that was despite Gunners' skipper Henry's return to the team.
The talismanic striker was soon into the action - yet in unfamiliar fashion - using his head to connect with Kolo Toure's deep cross to the far post.
But Blades' keeper Ian Bennett managed to get his fingertips to the Frenchman's point-blank effort and turn the ball around the post.
Yet it was the visitors, despite them lying bottom of the table and without a Premiership win, who were first to have an attempt on goal.
Chris Armstrong struck a decent free-kick, but Jens Lehmann proved equal to the shot, diving low to his right.
It was clear that Blades manager Neil Warnock - celebrating the 1,000th match of his managerial career - had sent out his men with orders to snap in the tackle and get forward when they could.
Alan Wright demonstrated United's fighting spirit after a tangle left him needing attention to a cut on his head.
And Freddie Ljungberg found Bennett equally stubborn when his shot was saved by the Blades' keeper.
Earlier, though, Bennett should have been beaten when Gallas was put through by Tomas Rosicky's pass, but the defender screwed his shot wide.
As United grew in stature and continued to stifle Arsenal, so the game became more scrappy - the midfield became congested and chances were scarce.
It was a pattern that continued for a while the interval, albeit with United pegged back a little more, but remaining resolute in defence.
Particularly Bennett, who produced a fine save to divert Ljungberg's shot over the bar.
But Arsenal began to dominate and Bennett was powerless to prevent Gallas scoring the goal his all-round play deserved when Arsenal's emergency left-back cracked his shot into the roof of the net to finish off a delicate move on 65 minutes.
It was a blow to United, who had fought bravely - and it appeared to knock them out of their stride.
Just four minutes later, Henry worked his way down the left flank and his low centre was fluffed by Jagielka who could only watch his intervention divert the ball beyond his own keeper.
And Henry rounded off a victory, with a score line that was a little flattering, when he headed in Emannuel Eboue's cross from the right.
Steve Kabba almost snatched a consolation for United, when he rose at the back post, but Lehmann made an athletic save to ensure a clean sheet.
Arsenal boss Arsene Wenger:
"We had to fight and Sheffield United played a very good game. They defended well and didn't hide when they had the chance to come out.
"We needed to make sure we didn't become too nervous and to continue to do things properly.
"I felt that all we need to do was keep calm and patient."
Sheffield United boss Neil Warnock:
"The players gave me everything and I could not have asked for more - it's all a manager can ask.
"Thierry Henry said to me when we were coming off, 'it was a very hard game and your boys have done very well' - and I think that was true.
"In the end, the difference was their quality. They were better than us."
Arsenal: Lehmann, Eboue, Toure, Djourou, Gallas, Ljungberg (Julio Baptista 78), Fabregas, Silva, Rosicky (Hleb 71), Adebayor (Van Persie 71), Henry.
Subs Not Used: Almunia, Flamini.
Booked: Fabregas, Eboue.
Goals: Gallas 65, Jagielka 69 og, Henry 80.
Sheff Utd: Bennett, Sommeil (Alan Quinn 78), Jagielka, Davis, Geary (Kozluk 78), Gillespie, Leigertwood, Armstrong, Wright, Kazim-Richards (Kabba 89), Hulse.
Subs Not Used: Bromby, Akinbiyi. Booked: Hulse.
Ref: A Wiley (Staffordshire).