Middlesbrough scrape through in FA Cup after Kenny clanger
The goalkeeper had repelled everything the Barclays Premier League side could throw at him when, 23 minutes into extra time, in his desperation to claim Mido's deflected shot, he helped the ball into his own net to hand Boro a quarter-final clash with Cardiff.
It was the most unkind of misfortunes for the 29-year-old, who had turned in a superb display to keep out the Teessiders' record signing Afonso Alves - on two occasions - Luke Young, Stewart Downing and Tuncay Sanli.
Indeed, had James Beattie's 90th-minute shot crept inside Mark Schwarzer's left post rather than gone marginally outside it, it would be the Blades welcoming Cardiff to Bramall Lane in the last eight.
On the balance of play, Boro were good value for their victory, but having dominated for long periods, they had failed to make the most of their pressure until they were handed a large slice of good fortune in front of a crowd of 28,108.