A late Dani Ceballos winner earned Arsenal a 2-1 quarter-final victory at Sheffield United on Sunday afternoon, ensuring they are still in contention for a 14th FA Cup trophy.
The Blades thought they had taken an early lead, only for John Lundstram's header to be ruled out for offside after a VAR check. Despite starting well, the hosts soon found themselves a goal down as Chris Basham gave away a penalty for a foul on Alexandre Lacazette. Up stepped Nicolas Pépé, who slotted the ball past Dean Henderson to put the visitors in front.
The Ivorian soon saw another shot pushed away by the Blades stopper, as Arsenal began to open the game up. With half-time looming, Oliver Norwood had his shot saved by Emiliano Martínez, before the lively Pépé found his effort inches away from extending the Gunners' lead.
After the break, the hosts looked more lively and had another goal disallowed, with John Egan's header ruled out for offside, before Basham nodded wide from close-range. After looking the better team in the half, they made their pressure eventually count as David McGoldrick took advantage of some poor defending to grab a late equaliser for Chris Wilder's side.
Yet after substitute Billy Sharp was denied by Martínez's close-range save, Ceballos' stoppage-time shot went past Henderson to put Arsenal back in front, and they held on to secure a trip to the semi-finals.
Key Talking Point
With Arsenal's defence coming under much scrutiny in recent weeks, the Blades were expected to put their opponents under intense pressure and make it an uncomfortable afternoon for the likes of David Luiz and Shkodran Mustafi.
But after a bright start, they seemed unable to trouble the north London side, with Oliver McBurnie failing to use his physical presence effectively. Chris Wilder's team often failed to get the ball into their attacking box and force their opponents into mistakes, as other teams have done previously.
They looked more willing to trouble the Gunners after the break, with McBurnie becoming more involved as the target man for Sheffield United. It eventually paid off, as McGoldrick took advantage of some slack set-piece defending to net an equaliser for the hosts.
Yet after Ceballos' late winner, they will rue their lack of clinical finishing that means their dreams of booking a semi-final place at Wembley are now over.
Starting XI: Henderson (6); Basham (5), Egan (6), Robinson (6); Baldock (6), Lundstram (6), Norwood (6), Fleck (7), Stevens (6); McGoldrick (7), McBurnie (6).
Substitutes: Berge (6), Freeman (6), Sharp (N/A).
While many of his teammates weren't as effective on Sunday, John Fleck was a strong presence in United's midfield.
The Scot constantly drove forward with the ball to help spark the Blades in attack, while he was also defensively solid in keeping out their opponents - the penalty aside.
Key Talking Point
With star striker Pierre-Emerick Aubameyang benched, many turned to record-signing Pépé to produce the goals for the Gunners. The Ivorian had previously netted a terrific strike at Brighton and looked like he was finally showing the finishing talents he was signed for.
As the first half wore on, the Ivorian gradually became a lively threat and caused problems for the hosts' defence with his pace. After netting his penalty, he looked determined to extend Arsenal's lead, with his effort before the break coming close to earning himself a second goal.
In the second half, he was noticeably more quiet, which was down to the Blades wrestling control of the game and putting the north London side's backline under pressure. Yet on the rare occasion that the visitors had the ball in their attacking half, the winger always seemed to be involved.
With Lacazette having a disappointing outing in front of goal again, much of the attacking responsibility will rest on Pépé's shoulders if Arteta's team are to go all the way in this cup tournament.
Starting XI: Martínez (6); Mustafi (6), Luiz (6), Kolašinac (6); Maitland-Niles (6), Willock (6), Xhaka (6), Tierney (6); Pépé (7*), Lacazette (6), Saka (6).
Substitutes: Holding (6), Ceballos (7), Nketiah (6), Sokratis (N/A).
As the game went on, it became clear that Pépé was Arsenal's most dangerous threat going forward.
His runs into dangerous positions constantly kept the Blades' backline on their toes, and the Ivorian was at the heart of the Gunners' best attacking moves throughout the game. With two goals since English football returned, he's a key figure for Arsenal's remaining league and cup games.
The Blades next host Spurs on Thursday night, while Arsenal will welcome relegation-threatened Norwich City to north London the night before.