Middlesbrough 1 Sheffield United 0 <i>(Aet)</i>: Boro profit from brave Kenny's misfortune

Boro new boy Afonso Alves (right) battle's with Sheffield United's Derek Geary last night (AP)

Middlesbrough as a club may be on a war footing with the Football Association but the luck of the Cup is clearly not being denied Boro by the "silly little men" of Soho Square as Boro chairman Steve Gibson knows them. It took a fluke of fairly outrageous proportions 113 minutes into this far from absorbing fifth-round replay to send Boro through to their third consecutive FA Cup quarter-final and, bearing in mind it is Cardiff City who have to come to the Riverside for it, a second semi-final in three years beckons Boro.

It will be at Wembley but Gareth Southgate's side will have to show considerably more vim if they are to get there first, then make the exercise worthwhile.

After £12.5m record signing Afonso Alves squandered two good chances in his 73 minutes on the pitch, the game hobbled into extra-time and was petering out towards a penalty shoot-out when Mido latched on to yet another hoisted cross into the Sheffield United area. Mido's header hit Matt Kilgallon and came back nicely for the Egyptian. He lashed at this one with a boot and it was goalbound until it deflected off United's indefatigable captain Chris Morgan.

But we were only at the beginning of a circuitous goal on a circuitous night. From Morgan the ball swooped upwards and struck the angle of post and crossbar. Paddy Kenny in the visitors' goal watched as all of this unfolded and must have thought the winner was past him at last.

But after the ball rebounded it suddenly dashed in Kenny's direction and, wrong-footed and flummoxed, he instinctively extended his right hand. Now facing his own line, Kenny's connection took the ball back across it.

Cruel does not start to describe such a moment: Kenny, Morgan, James Beattie and the excellent Stephen Quinn did not deserve to be on the losing team.

"You need a bit of luck in the Cup and Boro have had that," said United caretaker Kevin Blackwell. "They could go on to the final now. But I think it was particularly cruel on Paddy Kenny and for the announcer to call it an own goal, I think that was stupid."

"There's only one Paddy Kenny," sang the home fans after the goal. Their irony was not fitting: over two games across over three hours the Blades' keeper was as efficient as anyone.

Not that there were a stampede of candidates for that title.

With Alves's replacement Tuncay Sanli failing conspicuously to wrap up the night with a second goal – James Beattie making a contender for recovery tackle of the season to thwart the Turk – the two games had an emblem and the Championship men one last hope of an equaliser.

Sure enough, in their last attack, the ball dropped for Kilgallon in the Boro area and he met it sweetly. Sadly for him his shot smacked into Emanuel Pogatetz's midrift and seconds later the final whistle sounded.

So Cardiff travel to Teesside and they will take encouragement not only from Boro's bluntness against Sheffield United, but also from last season when Bristol City and West Bromwich Albion took Boro to replays and lost out only on penalties here.

It seemed set for another of those evenings and yet the match had actually started quite brightly, especially when compared to the turgid affair at Bramall Lane ten days ago. At least the pitch here was playable.

That left it up to the teams and both have the passing urge. The Blades may have robust figures such as iron captain Morgan but they also have neat individuals such as Quinn and Gary Speed. All lasted the two hours.

Much of it was spent on the back foot, but when they could be progressive, United were. But it was Boro who set the tone and the tempo and had Alves converted a ninth-minute header from Fabio Rochemback's inswinging corner, the whole occasion would surely have been straightforward.

Fifteen minutes later Stewart Downing skewed a shot having burst into the Blades' area following a creative one-two with Mido. Boro were getting closer and, it seemed, a breakthrough was imminent in that first half. But two minutes before the interval Kenny made a smart save with his feet to clear a Luke Young effort, Alves having done well, and the second half of normal time was a let-down after that, Alves having a 65th minute effort stopped by Kenny.

Normal time finished with Beattie stabbing a half-chance into the side-netting, but extra-time saw Boro find some rhythm again. That, however, does not explain their winner.

"In the end our guts got us there," said Southgate.

Middlesbrough (4-4-2): Schwarzer; Young, Hines, Pogatetz, Grounds; Boateng, Rochemback (Johnson, 104), Arca (O'Neil, 77), Downing; Alves (Tuncay, 73), Mido. Substitutes not used: Turnbull, Cattermole.

Sheffield United (4-4-2): Kenny; Naysmith, Morgan, Kilgallon, Geary; Stead (Martin, 59; Shelton, 91), Quinn, Speed, Tonge; Beattie, Sharp (Hulse, 73). Substitutes not used: Armstrong, Ehiogu, Hulse.

Referee: P Walton (Northamptonshire).