Arsenal 1 United 1 (3-5 penalties)
EXTRA-TIME
Heading into extra-time, Arsenal almost took the lead just after the clock had struck 100 minutes, with Havertz nearly finding Leandro Trossard for a tap-in, but Matthijs de Ligt did just enough to put the Belgian off.
Zirkzee went close shortly after the break but his shot was tipped behind for a corner by Raya.
It was end-to-end drama at this point, with Amad popping up to threaten with a header in 110th minute. Both went close, but penalties were needed to separate the two rivals.
PENALTIES
Bayindir had been the hero a couple of times before in this game, and so he was again, diving to his left to tip Havertz's spot-kick behind, giving United the advantage in the shootout.
And that was an advantage taken by Zirkzee, under all the pressure, as he slotted away the decisive penalty in front of the travelling fans, securing the Reds' place in the next round of the FA Cup.MATCH DETAILS
Arsenal: Raya; Timber (Partey 101), Saliba, Gabriel, Lewis-Skelly (Trossard 91); Jorginho (Tierney 113), Merino (Rice 73), Odegaard (c); Jesus (Sterling 40), Havertz, Martinelli.
Subs not used: Neto, Kiwior, Zinchenko, Butler-Oyedeji.
Goals: Gabriel 70.
Booked: Gabriel, Havertz.
United: Bayindir; De Ligt, Maguire (Yoro 104), Martinez; Mazraoui, Ugarte (Malacia 91), Mainoo (Collyer 81), Dalot; Fernandes (c), Garnacho (Amad 80); Hojlund (Zirkzee 81).
Subs not used: Onana, Casemiro, Eriksen, Antony.
Goals: Fernandes 52.
Booked: Martinez, Fernandes, Dalot, Mainoo, Maguire.
Sent off: Dalot (second yellow card).