John Mullin produced a finish Ruud van Nistelrooy would have been proud of to earn First Division Rotherham a Premiership scalp after 90 crashing FA Cup minutes at Millmoor.

Mullin charged down the flank onto Chris Sedgewick's through-ball in the 54th minute before drawing wide and hammering the Millers' second goal past Southampton keeper Paul Jones in much the same way as the big Dutchman had done the business against the Saints on Sunday.

But Ronnie Moore's rapid risers were forced to cling on through 15 nerve-jangling final minutes for their third round upset after Marian Pahars whacked home a 70th-minute penalty following a needless push on Kevin Davies by Andy Monkhouse.

Davies' introduction in the 62nd minute made a huge difference to Gordon Strachan's men who camped in the Millers half for the final portion of the game and came agonisingly close to salvaging a replay.

But it was the Millers who held out and referee Matt Messias' whistle after three minutes of added time, which seemed to last a lifetime, provoked a roar which could have been heard on the south coast.

As the seconds ticked by Ecuadorian striker Agustin Delgado had seen a shot blocked inside the box on his full debut and was then inches away from connecting with Pahars' left-wing cross from virtually underneath the crossbar.

Richie Barker had given Rotherham the lead after 39 breathless minutes when he soared in unmarked at the far post to head Kevin Watson's free-kick past Jones.

The half-time advantage was everything Rotherham deserved for their physical pressure and indeed they ought to have gone ahead much earlier when Martin McIntosh took advantage of a mistake by Paul Telfer to hit a left-foot shot inches wide of Jones' goal.

The Saints' chances were few and far between, with Delgado missing the best chance when his touch onto Jason Dodd's right-wing cross was deflected out for a corner.

Strachan's appearance on the touchline for the start of the second period made a big difference as Saints got used to fighting back from behind - the opposite of last season's horror at Prenton Park when they had blown a 3-0 half-time lead against Tranmere.

Pahars came close with a point-blank header straight at Mike Pollitt in the home goal but the Millers broke and Mullin's heroics seemed to have secured the home side's fourth round date against Crewe.

But Strachan's appearance was nothing compared to the impact of Davies, who replaced Fabrice Fernandes, and who within seconds had flung over a right-wing cross for Delgado which Pollitt grabbed underneath his own bar.

Saints' pressure became relentless as Rotherham hung onto a famous win by their fingertips.

Pahars and Delgado missed good chances and Matt Le Tissier's introduction in place of the Ecuadorian with 10 minutes to go cranked up the tension to fever pitch.

Rotherham could have eased the pressure when Mullin unleashed another dramatic effort with four minutes to go which flashed just wide of Jones.

Teams:

Rotherham: Pollitt, Hurst, Scott, Swailes, McIntosh, Sedgwick (Daws 84), Watson, Mullin, Monkhouse (Talbot 71), Warne, Richard Barker.

Subs Not Used: Gray, Robins, Branston.

Booked: Warne.

Goals: Richard Barker 39, Mullin 55.

Southampton: Jones, Dodd, Bridge, Williams, Lundekvam, Svensson, Marsden, Telfer, Fernandes (Davies 62), Pahars, Delgado (Le Tissier 79).

Subs Not Used: Moss, Monk, Tessem.

Goals: Pahars 70 pen.

Att: 8,464

Ref: M Messias (York).