Arsenal will have to navigate a fifth-round replay at Hull City if they are to defend the FA Cup after a dour goalless draw at the Emirates Stadium on Saturday.
Both Arsene Wenger and Steve Bruce fielded weakened sides for their third FA Cup meeting in three seasons and, though the Gunners controlled proceedings against their Championship opponents, they were met with continued resistance from goalkeeper Eldin Jakupovic.
Danny Welbeck and Theo Walcott were both denied in the first half before Joel Campbell saw a free-kick turned onto the post and Alex Iwobi was denied from distance as Arsenal, largely camped in the Hull half, battled to break the deadlock.
Wenger introduced Olivier Giroud and Alexis Sanchez from the bench but Arsenal were unable to find a breakthrough, meaning they will meet again at the KC Stadium.
Wenger had said this week he would give Mohamed Elneny the chance to impress and the Egypt international threatened with just six minutes on the clock - his shot striking Alex Bruce on the arm with referee Mike Dean waving away Arsenal's shouts for a penalty.
Welbeck aimed a header straight at Jakupovic after good work from Walcott, and the former Manchester United striker - making his first Arsenal start in 10 months - was denied again by the goalkeeper with a low shot from 10 yards out as the Gunners began to crank up the pressure.
Jakupovic reacted superbly to divert Walcott's effort from a tight angle away from the bottom corner but Arsenal were given a scare when Harry Maguire went down under slight contact from Campbell inside the area, though Dean opted to book the Hull defender for simulation.
Jakupovic denied Walcott again from close range just after the break before Iwobi's effort was deflected past the far post, as Hull continued to invite pressure from the home side.
The fingertips of Jakupovic touched Campbell's free-kick onto the base of the post and the 31-year-old palmed away a curling Iwobi effort as Arsenal became increasingly desperate.
Giroud saw a shot saved comfortably a few moments after coming on but Hull spurned a rare chance of their own on the counter-attack when David Meyler fired into the side-netting after being played through by Nick Powell.
Arsenal continued to push late, with Sanchez seeing a free-kick punched away and Alex Oxlade-Chamberlain's header caught on the line in the dying seconds, but Hull held on to force a replay which neither the title-chasing Gunners - who face Barcelona in the Champions League next week - nor the Championship promotion hopefuls will consider an ideal scenario.