Before kick‑off Tony Mowbray reminded his players that, despite being much improved under Martin O'Neill, Sunderland are not quite Barcelona. Clearly heeding that message, an under-strength Middlesbrough forgot their recent Championship travails and came back from a goal down to offer their visitors a most exacting replay workout.

Ironically Mowbray had added that O'Neill lacked a Lionel Messi or a Cristiano Ronaldo, although Stéphane Sessègnon offered him "bits and pieces". Deep in extra time Sessègnon duly treated everyone to one of his match‑winning cameos.

Having set up Connor Wickham he watched the young substitute striker take too many touches before miscuing. Pouncing on the loose ball, the Benin forward shot low into the bottom corner to earn a fifth‑round date with Arsenal at the Stadium of Light. "It was exciting and really hard work," said O'Neill. "But we deserved it."

Sunderland spent much of the first half constructing geometrically pleasing passing triangles but the deadlock was broken courtesy of a goal straight from the route one manual. John O'Shea's long ball was knocked down by Fraizer Campbell, falling for Jack Colback to seamlessly tame before squeezing a left‑foot half‑volley into the top corner.

Suitably stung, Boro rallied. Almost immediately Tony McMahon saw a fierce goalbound shot blocked and then Simon Mignolet saved well from Curtis Main. A young striker released by Darlington last spring, Main was making his first start.

Had it not been a prime contender for the coldest night of the winter on Teesside the crowd would surely have been signficiantly higher than 26,707. Those that braved the bitter chill saw Main perform wonders to beat O'Shea and head down into the path of Lukas Jutkiewicz. With Michael Turner wrong-footed, the former Coventry City striker's subsequent half‑volley eluded Mignolet.

With Joe Bennett shining at left‑back, Mowbray's impressive defence held firm until Sessègnon's denouement. "Stéphane's outstanding," said O'Neill, who was missing a handful of injured players including his captain, the Boro old boy Lee Cattermole.

As Sunderland fans waiting to board their homebound coaches chorused "We're going to Wemberlee", Mowbray remained sanguine. "I'm disappointed," said Boro's manager, whose overriding priority has always been promotion. "But there's no doubt in my mind that, if we ever get out of this division, my team can play in the Premier League.

"We've shown we could match Sunderland over two games in which Martin fielded his strongest available teams – and I'm pleased for Curtis Main that he's held his own against a Premier League defence."