Louis Saha scored a debut goal and Ruud van Nistelrooy celebrated signing a new contract with the winner as Manchester United beat Southampton.
Saints fought back from two goals down to threaten a shock before Van Nistelrooy scrambled the decider in a fluctuating Old Trafford encounter.
Debutant Saha's deflected free-kick put United ahead before Paul Scholes scrambled home a second before half-time.
Kevin Phillips struck from long-range either side of the interval to draw Southampton level, but Van Nistelrooy scored on the hour to give United the three points.
Saha was handed an instant debut by United boss Sir Alex Ferguson, who received a rousing reception before kick-off when he came on to the pitch to celebrate signing his own new contract.
And the former Fulham striker made a dream start when he put United ahead after 17 minutes.
He fired a free-kick in from 20 yards, and even though it took a crucial deflection off Phillips, Saha will do all he can to claim the goal.
And he was involved again when United doubled their advantage after 36 minutes.
17 mins: Saha puts Man Utd in front
36 mins: Scholes doubles Man Utd's lead
37 mins: Ormerod deflects Phillips' drive past Howard for Southampton
52 mins: Phillips equalises for Southampton from long range
60 mins: Van Nistelrooy restores Man Utd's lead
Saha's powerful shot was fumbled by Antti Niemi, and Scholes pounced in predatory fashion from eight yards.
But just as United looked to be moving into the comfort zone, Southampton hit back in the same fortuitous manner that had seen them go behind.
Phillips' long-range drive was diverted off Brett Ormerod to leave United goalkeeper Tim Howard wrong-footed.
Ormerod may claim the strike, but there was no doubt who the scorer was when Phillips levelled for Southampton after 52 minutes.
He took advantage of slack work by Wes Brown, who had a nightmare, to flash a finish past Howard from 25 yards.
And it took a desperate save from Howard three minutes later to deny Ormerod after more confusion between Brown and Quinton Fortune.
Southampton paid the price five minutes later as United went ahead in controversial circumstances.
United initially appealed for a penalty when Fabrice Fernandes handled Ronaldo's free-kick.
Referee Graham Barber awarded a free-kick, and Van Nistelrooy - who has just signed an extended deal poked home from eight yards as Southampton appealed for offside.
But Southampton refused to lie down, with Danny Higginbotham hitting the bar with an acrobatic overhead kick and Phillips missing a cross from substitute James Beattie virtually on the goal-line.
Man Utd: Howard, O'Shea, Brown, Silvestre, Fortune,
Ronaldo (Butt 90), Phil Neville, Keane, Scholes,
Saha (Fletcher 70), van Nistelrooy.
Subs Not Used: Carroll, Kleberson, Forlan.
Southampton: Niemi, Dodd, Hall, Higginbotham,
Le Saux (Kenton 80), Anders Svensson, Delap, Telfer,
Fernandes (Pahars 67), Phillips, Ormerod (Beattie 67).
Subs Not Used: Smith, Folly.
Booked: Higginbotham, Ormerod.
Referee: G Barber (Hertfordshire).