With the fallout still radioactive from the Luis Suárez judgment, for his racially aggravated abuse of Patrice Evra, it was easy to forget, for a moment, that there was some football to be played. Manchester United did not forget. With a performance of ruthless focus, they swatted aside Fulham to maintain not only their imperious away form but their pursuit of Manchester City.

Sir Alex Ferguson's team is the only one in the country yet to taste defeat on their domestic travels and a blemish was never likely here, from the moment that Danny Welbeck enjoyed the first offer of hospitality from the Fulham defence. Martin Jol, the home manager, wore a thunderous expression as United made the game safe by half-time. Nani scored the second and made two more while Ryan Giggs embellished yet another personal legend by contributing his first league goal of the season. He has now scored in all 20 Premier League campaigns.

Fulham were better in the second half, although it would have been remarkable if they had been any worse, but United finished in style, with Wayne Rooney scoring with a deliciously swerving shot from 25 yards. He was trumped, though, for the evening's finest goal by the substitute Dimitar Berbatov, who guided Antonio Valencia's low cross into the far corner with a backheel of sumptuous execution. Never mind Giggs. It was his first league goal of the season.

When things click for Berbatov, it is easy to presume that simply everything must have gone right for United. Not quite. There was concern for Phil Jones, who started at right-back but left the fray early with a suspected cheekbone fracture, having caught a nasty-looking elbow from Clint Dempsey in a second-minute aerial challenge.

He played on but when he lost his bearings to allow Bryan Ruiz in behind him, compelling him to make a saving tackle inside his penalty area, his number was up. He had been pepped by smelling salts but looked dazed as he left the field in the 20th minute.

There were spicy tackles. Jonny Evans was horribly late on Moussa Dembélé while Ashley Young, who had come on for Jones, left the ground when he flew into a reckless one on Dickson Etuhu. He came off worse, when the Fulham midfielder saw him coming, although Ferguson, curiously, blamed Etuhu after Young was forced off.

"There were some very aggressive tackles in the second half and Ashley Young paid the price of that," Ferguson said. "He will be out for two or three weeks. Jones was caught by an elbow, although I don't think it was intentional. We'll send him for an X-ray and we'll see tomorrow but it doesn't look great."

United suffered another blow when they learned that their ticket allocation for the third-round FA Cup tie at Manchester City has been restricted to 5,900, significantly less than the 15% of capacity to which they believe they are entitled.

Ferguson reported that Rio Ferdinand, who took a knock at QPR on Sunday and did not play here, would miss the Wigan game on Boxing Day but "should be available for Blackburn" on New Year's Eve. The manager was forced into a further defensive reshuffle when Jones was led from the field, Valencia dropping into right-back.

Jol might have wondered if his pre‑match exhortations were for nothing when Ruiz and Chris Baird allowed Nani to run and cross for Welbeck to sweep home. United worked a short corner routine for the second goal, Giggs whipping over a cross for Nani, of all non-aerial specialists, to glance a header past David Stockdale and the third followed more hands-off Fulham defending. Nani strolled into the area, squared and Giggs's shot looped up off Philippe Senderos and arched over Stockdale. Jol called it a "horror show".

Fulham created second-half chances, with Anders Lindegaard, given a starting opportunity in the United goal, making smart saves to deny Dempsey and Andy Johnson, twice. At the other end, Welbeck chipped over when one-on-one with Stockdale before Rooney and Berbatov sculpted the final flourish.

Ferguson made no comment on the Suárez-Evra case. "We've said nothing all along," he said. "It's in the hands of the FA and that's how it's going to stay." He was happier to salute "one of our best performances of the season".