Dani Ceballos sent Arsenal through to the FA Cup semi-final after a dramatic last-gasp winner.
Club record signing Nicolas Pepe opened the scoring, but only after submitting his entry for one of the misses of the season in the 1-0 defeat at Bramall Lane in October.
But he delivered an assured finish from the penalty spot in the 25th minute to take the 13-time winners back to Wembley for the last four. It was a good performance from Pepe, whose miss from six yards spelt the beginning of the end for Unai Emery.
Since then, Pepe has suffered a crisis in confidence and while Lille clearly saw Arsenal coming – and will still be in a state of shock after getting £72milion for him – he is a player still capable of flashes of quality.
The big question is whether he can become more consistent. But in a hard-fought win, another of last summer’s signings left wing-back, Kieran Tierney, delivered an excellent performance and what a good addition he will prove to be.
As for the Blades, the break has done themselves no good and they appear to have run out of steam.
Yet you could understand why many would have put a few quid on a home win when you looked at the Arsenal team sheet.
It was no surprise that Matteo Guendouzi and Mesut Ozil failed to make the trip to Yorkshire but Mikel Arteta’s squad selection was odd.
Pierre-Emerick Aubameyang started on the bench and the captaincy was handed to his replacement Alexandre Lacazette rather than David Luiz.