(CNN) -- Manchester United rubberstamped an FA Cup fourth round home clash against Tottenham with an emphatic 3-0 win at Championship strugglers Southampton on Sunday.
Nani stroked home a penalty as Manchester United eased into the fourth round of the FA Cup.
Goals from Danny Welbeck, Nani and substitute Darron Gibson won the day for United who rested Cristiano Ronaldo and Carlos Tevez and had Wayne Rooney on the bench.
The all-Premier League clash with Spurs on the weekend of 24-25 January could turn out to be a rehearsal for the League Cup climax with both sides facing two-leg semifinals before they meet.
United were always in charge at Southampton and the opening goal arrived after 19 minutes through Welbeck who nodded in from close range after Nani's corner was headed against the bar by John O'Shea.
Southampton's task became even more difficult after 35 minutes when Matt Paterson was red carded after a lunge on United defender Nemanja Vidic.
It looked hopeless a minute after the restart when referee Mike Riley awarded United a penalty for handball against David McGoldrick who was deemed to have used an arm to deflect Nani's free kick.
Nani converted the spot-kick before Kelvin Davis denied Welbeck a second goal when he tipped his shot over in the 49 minute.
United's dominance was such that they replaced Ryan Giggs and Michael Carrick with Gibson and Rodrigo Possebon -- although Rooney made an appearance after 62 minutes.
The England striker set up the third with a cross for Gibson to fire home after 81 minutes and was later denied when his 25-yard volley was well saved by Davis
Aston Villa manager Martin O'Neill admitted his team had survived a real test after they claimed a 2-1 win in their third round clash at Gillingham.
James Milner scored the decisive goal from the penalty spot in the 79th minute after Ashley Young had gone down in the area.
Simeon Jackson earlier turned Zat Knight and fired home a 57th-minute equaliser to cancel out Milner's first-half opener.
O'Neill told ITV1: "It was really tough. I came here last week and knew it would be tough. If the players didn't know it would be tough they did after 10 minutes. They (Gillingham) are very strong. They played very well and good luck to them this season."
O'Neill praised match-winner Milner, particularly for his opening goal which he coolly slotted into the corner after a neat one-two with Stiliyan Petrov. "It was a terrific goal by James, very well worked," he said.
O'Neill and Gillingham boss Mark Stimson exchanged words on the touchline in the second half, but O'Neill played down the spat saying: "We shook hands in the end."
Villa are away to either Cheltenham or Doncaster in the fourth round.