Rampant Manchester United crushed Birmingham as Dimitar Berbatov hit a hat-trick with Ryan Giggs masterful. Berbatov nodded in on the line after 95 seconds before firing home easily after Roger Johnson had given the ball away. With Giggs lifting the unbeaten league leaders to heights they have rarely hit this season, the veteran finished off a brilliant move just before the break. Hungry Berbatov then converted a Giggs cross for his third before Nani slotted a fifth with Birmingham on their knees. Leaders United now sit two points clear of second-placed Arsenal with a game in hand, and their unbeaten league record was never in danger as the lowly visitors looked like a team without the fight - or nous - required to claim a first win against the Red Devils since 1978. Birmingham do have a Carling Cup second-leg semi-final to think of, yet United were utterly ruthless while Berbatov is now the Premier League's top scorer after recording his third hat-trick of the season. The Blues dropped their top scorer, Craig Gardner, to give 19-year-old Jordan Mutch a debut at Old Trafford. But it was 37-year-old Giggs who looked like a care-free teenager as he glided across the pitch he knows so well to breathtaking effect. The Welshman's first impact helped put the hosts in control within 95 seconds. His whipped right-wing corner was nodded on off the back of John O'Shea's head for unmarked Berbatov to nod in from no more than six inches. With the ball quite clearly going in some might say it was selfish, but manager Sir Alex Ferguson - and Berbatov's team-mates - are likely to be happy watching the languid Bulgarian hungrily stealing goals while wearing a broad smile. With United's movement flummoxing the visitors, Berbatov saw his low shot saved well by Ben Foster on his first return to Old Trafford. Centre-back Chris Smalling - in as a replacement for the injured Rio Ferdinand - then just failed to head in cross from Giggs which had been cleverly clipped to the back post using his weaker right foot. Nani then sliced a shot into crowd as he sought to find the top corner, with Birmingham failed to put in the biting challenges which so often characterise high-paced Premier League football. When they did compete, former Barcelona man Alexander Hleb trod on Michael Carrick's ankle, a challenge which causing the midfielder to be replaced by Darron Gibson. After an excellent David Bentley cross fizzed across United's penalty area without being capitalised on, Nani then sold a David Murphy - and most of the crowd - an outrageous dummy before hitting an equally outrageous cross-shot that went out for a throw-in. But Johnson's misplaced pass on the half-hour saw Anderson pounce to pass instantly forward to Wayne Rooney. He fed Berbatov with ease and, cutting in from the left unchallenged, he smacked a low shot through Birmingham's hapless back-line past Foster. Exhibiting his active imagination, the former Tottenham star then went so close to curling a teasing toe-poker with the outside of his boot into a tiny gap the corner of the net. Gibson soon lashed a left-foot shot at Foster after a thrilling passage of play. Uplifted Giggs drove a fine low shot towards the bottom corner but a slight - but significant - deflection carried the ball just wide for a corner after Birmingham's appeals for a penalty were dismissed when Keith Fahey's cross hit John O'Shea on the arm. The onslaught peaked in spectacular style just before the break as Old Trafford was treated to a rare sight - Berbatov winning the ball back with a committed sliding tackle. Rooney picked it up to execute a superb back-heeled one-two with the Bulgarian. The England striker then looked up to curl a perfect low cross into the box for onrushing Giggs to side-foot stylishly high into the net with his trusted left foot. Out-and-out striker Cameron Jerome replaced Hleb for the second period as Birmingham sought to play more on the front foot. But it was to little effect as unmarked Rooney inexplicably managed to skim a header wide from two yards when Nani's had crossed after once again twisting Murphy inside out. Bentley did bundle past Anderson to fire a shot just wide yet, despite their endeavour, Birmingham looked too dispirited. United's fourth goal came in the 53rd minute when Rooney deliciously brought the ball down from sky to remind everyone of his natural ability before passing to Giggs easily on his inside. The poised Welshman waited before crossing low for Berbatov to lunge ahead of Murphy to steer a smart finish into the roof of the net for his 18th goal of season in all competitions. With the game won, Michael Owen then replaced Giggs before Fahey managed to miss a chance from Bentley's cross following a rare mistake from Nemanja Vidic. The Birmingham midfielder was just two yards out but he could not swivel his body back to connect with the ball in time. Erratic-but-gifted Portuguese winger Nani then screwed a simple shot awry before setting free Berbatov, who dragged a good chance wide to add his fourth. Nani's 76th-minute goal summed up Birmingham's state of mind as he skipped across the screen of their heavy-footed defence to slam a powerful goal past Foster from 15 yards into the corner of the net. Source: BBC