James Beattie: target of Warnock's fury (GaryMPrior/Allsport)

Warnock was trembling with rage after his team's 1-0 defeat at Southampton after what he perceived was a deliberate dive by James Beattie under a challenge from United goalkeeper Simon Tracey.

For 73 laborious minutes Southampton had pounded away with increasing frustration and lack of imagination. Then Tracey dropped a speculative long range effort from Wayne Bridge and, as Beattie came in to punish the error, he tumbled under the keeper's desperate attempt to redeem his blunder.

David Elleray pointed to the spot and Jason Dodd duly converted Southampton's first penalty of the season. As United's protests continued, Elleray sent off midfielder Bobby Ford for dissent. Warnock said: 'The higher the division, the better the conmen.

My team's problem is that we don't have enough conmen. We have to learn to con the referee as Southampton did all afternoon.' But Saints striker Kevin Davies, still a United fan at heart despite being rejected by the club as a 14-year-old, denied Warnock's accusation.

Davies said: 'There is no way James would fall over looking for a penalty. He goes for goal. He said that when he tried to go around the keeper he had his legs taken away from him.' Warnock may face an FA investigation because he accused Elleray of needing binoculars to give the penalty decision from his position in the middle of the pitch.

'I don't care,' said Warnock. 'I'm deflated and bitterly disappointed because we have been knocked out of the FA Cup by a team that were no better than us. Southampton have not beaten us. The officials have.' Dodd believed justice was done. He said: 'It looked a penalty to me and I think their protests were more in frustration because they had defended so well for so long.'

Portsmouth, now with one win in 13 games, were beaten 2-1 at home by Tranmere. Lee Bradbury gave Pompey an early lead but Steve Yates equalised in the 44th minute and Andy Parkinson clinched victory in the 69th minute. Bradbury said: 'We made four changes which didn't help but we made a great start and had the chances to make the game safe.

Their keeper made some great saves but we conceded two sloppy goals which has been the story for most of the season.' Grimsby boss Lennie Lawrence was relieved after a 1-1 draw at Wycombe.