Manchester United began the day with the news that everyone connected with the club had been hoping to hear: that 18-year-old Adnan Januzaj had been tied down to a five-year contract, but ended it by conceding a scruffy goal at an 89th-minute corner to squander two points against Southampton.

Mauricio Pochettino's visitors were good value for their draw, as it happened, but David Moyes's shaky start at Old Trafford continues. United have won one league game at home all season, against newly promoted Crystal Palace, and since then they have picked up four points from a possible 12.

Januzaj was largely responsible for that, with his two goals in an impressive full debut at Sunderland, though in the excitement of introducing a teenage sensation, it tended to be overlooked that the United defence had looked fragile in that game, and Wayne Rooney and Robin van Persie were not hitting it off as well as had been hoped in attack.

The pair were involved in the goal that gave United the lead against Southampton, Van Persie picking up the rebound when Rooney's shot had been saved, but both players later hit the woodwork and Moyes complained that the home side should have put the game to bed by the time another defensive lapse cost them a win.

"I am disappointed, we have got to do better," the United manager said. "We wanted to get a bit of momentum going and I told the players at half-time that a single goal might not be enough. We can work on the defending, but we should have had the game finished off by the time Southampton equalised. We created enough good opportunities."

Moyes denied the absence of Sir Alex Ferguson in the home dugout had reduced the fear factor for opponents coming to Old Trafford, following West Bromwich Albion winning quite comfortably in the previous home match and Southampton refusing to lie down once United took the lead. "I don't think that's the case; the fear factor comes through the players United have, not the manager," he said.

Ferguson himself believes it would be highly laudable for Moyes to claim any silverware this season. "For David, winning a trophy would be a fantastic achievement," Ferguson told MUTV. "No matter what it is – the League Cup, FA Cup, European Cup or Premier League. We've always had priorities obviously and David is aware of that but I hope he achieves it." He added: "The key for David is not to look to do anything better or less but just to maintain what the club has been for 20-odd years and keep the success going. It is not easy winning a trophy in our league because you could say there are six teams fighting for the league."

Ferguson is certain Moyes will be given the space to do the job, though, given the vast amount of experience among the Old Trafford hierarchy. "He has great support at the club," he said. "It is a fantastically run football club. There are absolutely no issues about it. Every club needs a little bit of luck and hopefully we'll get the luck."

Pochettino said it was strange to come to Old Trafford and not see Ferguson on the sidelines, though he thought Moyes would succeed eventually. "It cannot be easy for David to be under Sir Alex's shadow, but he is a great manager and a great person. I am sure he will be as successful," the Southampton manager Pochettino said.

The only good news for United was that Januzaj was once again impressive, helping create the opening goal and only being denied a spectacular second-half strike by a flying save from Artur Boruc. "He didn't disappoint," Moyes said.

"He came up with a lovely pass for the first goal and he was involved in some of our best moves. He's a very talented player and he didn't look out of place. He took a few heavy tackles, but that didn't worry him either, he's got a very good temperament. Of course I am delighted about his new contract. The club have been trying to get him to sign for a few months, even before I came."