Arsenal scored two quickfire second-half goals to return to winning ways in the Premier League and leave Sheffield United without a point so far this season, although Republic of Ireland striker David McGoldrick did net the Blades' first league goal of the campaign.
The Gunners had won their opening two games before losing at champions Liverpool on Monday - but Bukayo Saka and Nicolas Pepe struck inside three minutes of one another to seal a hard-fought 2-1 victory over the Blades, with McGoldrick scoring a fine consolation for the visitors.
Arsenal boss Mikel Arteta named a few surprises in his starting line-up as Mohamed Elneny and Dani Ceballos started in midfield and Eddie Nkeitah was preferred to Alexandre Lacazette to spearhead the attack.
Nketiah had a fine early chance after being picked out with a ball over the top, but a poor touch took him wide of goal and the opportunity was lost.
Blades boss Chris Wilder was left fuming as David Luiz escaped what could have been an early red card. The Arsenal defender allowed the ball to roll past him and pulled back Oliver Burke's shirt as the forward burst through as a result - but referee Lee Mason was unmoved.
The opening half-hour saw little in the way of goalmouth action but Pierre-Emerick Aubameyang came close to opening the scoring with a little under 10 minutes left of the half.
Goalkeeper Aaron Ramsdale's clearance only reached Ceballos, who teed-up his captain for a fine, curling effort which the Sheffield United goalkeeper did well to tip behind.
It was then Arsenal's turn to call for a red card as Aubameyang was upended by Sander Berge, the Norway midfielder booked for the foul.
As a result of the challenge, Aubameyang was still limping when he headed down the tunnel at half-time - but he emerged after the interval unscathed.
He was inches away from turning home a Ceballos pass as Arsenal's push for an opening goal continued in vain.
With chances at a premium, Arteta turned to his bench and introduced Pepe in place of Nketiah, rejigging his forward line to deploy Aubameyang through the middle.
The alterations did the trick as the first move of quality in the game saw Arsenal break the deadlock on the hour.
Elneny burst into the box and found Aubameyang, whose ball in to Hector Bellerin saw the full-back cross for Saka to head home at the back post - a great way for the 18-year-old to toast his first senior England call-up.
Just three minutes later and the points were secured, Bellerin again the provider as he slipped the ball through to Pepe.
The Ivory Coast forward broke into the box unchallenged and fired low past Ramsdale for his first goal since he turned home a penalty in the 2-1 FA Cup quarter-final win against Sheffield United in June.
As is often the case with Arsenal, things were not all plain sailing as McGoldrick curled in a fine goal from 20 yards to bag Sheffield United's first league goal of the season.
But they could not find a way to pick up their first points of the campaign as Arsenal saw out the closing stages to secure the win.