Howard Webb, widely considered to be the best referee in England, inadvertently played a starring role in the downfall of Birmingham City last night and admitted that it was the lowest point of his professional career. Not only did he deny the home team what appeared a cast-iron penalty, the Sheffield official was able to claim an assist that allowed the Coca-Cola Championship leaders to break away and score their clinching goal.

“I am disappointed to have an influence on a goal like that,” Webb said after his unintended interception left Birmingham stranded as Andy Keogh ran upfield and Sam Vokes scored Wolves’ second goal. “It is probably the lowest point of my professional refereeing career.

“You want the world to swallow you up at that moment, but the rules state that the ball is in play so we can’t stop the game for it. It’s Sod’s law that they go and score from it.

“I have spoken to the management of Birmingham City and they have been outstanding and accepted it. They have shown no animosity at all. But I was almost more disappointed about the penalty incident.”

These were critical moments, but Wolves deserved to win and will play Middlesbrough at home in the fourth round a week on Saturday.

Seven minutes before the interval, Keogh had blasted in his first goal since October 4 after running clear on to Kightly’s delicious through-pass. But shortly after, Webb denied Birmingham what appeared a certain penalty as Richard Stearman felled Marcus Bent with a mistimed tackle.

“We felt aggrieved,” Alex McLeish, the Birmingham manager, said. “We felt it was a bad tackle on Bent. But Howard’s the man on the spot and a superb referee. I just felt on this occasion he got it wrong. It was a great set-up pass from Howard again. Nothing went for us.”

With Birmingham trailing and pushing forward early in the second half, Webb could not get out of the way of Radhi Jaidi’s attempted pass, leaving Wolves with men to spare on the counter-attack. The ball fell to Keogh, who sprinted half the length of the field before playing in Kightly on the overlap. Kightly crossed for Vokes to score and the St Andrew’s crowd were left howling at the injustice of it all.

While McCarthy’s decision to rest his prolific strike force of Sylvain Ebanks-Blake and Chris Iwelumo was rewarded, Birmingham knew this was not their night when Cameron Jerome turned superbly on the edge of the penalty area and unleashed a brilliant shot against the crossbar. Nor was it Webb’s, but at least he had the courage to come out and admit it.

Birmingham City (4-4-2): Maik Taylor — S Parnaby, R Jaidi, L Ridgewell, F Queudrue — K Agustien (sub: S Kelly, 83min), L Carsley, N Quashie, R Shroot — M Bent (sub: D Johnson, 46), C Jerome. Substitutes not used: C Doyle, Martin Taylor, A Sammons, M McPike. Booked: Quashie, Jaidi.

Wolverhampton Wanderers (4-4-2): W Hennessey — D Edwards, R Stearman, N Collins, S Ward — M Kightly (sub: S Ebanks-Blake, 82), K Henry, D Jones, G Friend — S Vokes (sub: C Iwelumo, 78), A Keogh. Substitutes not used: C Ikme, M Jarvis, J Shackell, D Potter, M Hill. Booked: Stearman.

Referee: H Webb.

Revised fourth-round draw
Kick-off 3.0 unless stated

Jan 23: Derby v Nottingham Forest (7.45)
Jan 24: Hartlepool v West Ham (12.40)
Hull or Newcastle v Millwall
Sunderland v Blackburn
Chelsea or Southend v Ipswich
Cheltenham or Doncaster v Aston Villa
Torquay v Coventry
Kettering v Fulham
Watford v Leicester or Crystal Palace
Manchester United v Tottenham (5.15)
Jan 25: Cardiff City v Arsenal (1.30)
Liverpool v Everton (4.0)
TBC: West Brom v Queens Park Rangers or Burnley
Portsmouth v Swansea
Sheffield United v Charlton
Wolves v Middlesbrough