Premier League leaders Manchester United extended their 100 per cent record over Wigan Athletic with a 4-0 win at the DW Stadium.Javier Hernandez took just 17 minutes to justify his selection ahead of Dimitar Berbatov in the attack by scoring the opener before adding a second 15 minutes from time.Wayne Rooney and Fabio da Silva then struck in the closing stages to put the gloss on the win that opens up a four-point gap between United and Arsenal at the top of the table.United have now won all 13 matches they have played against Wigan in all competitions, scoring 41 goals and conceding just four in the process. Rooney, who has featured in every one of those matches, has a personal haul of 10 against the Latics.Rooney deserved his goal to cap off an influential performance, and he helped get the ball rolling for the opening goal. The England striker combined with Nani down the left wing and the Portuguese picked out Hernandez with a low ball to the near post that the Mexican turned past Ali Al-Habsi.It was the eighth league goal of the season for the Mexican, known as 'Chicharito' - United have never lost when he has scored. Nani's assist was his 12th of the season, more than anyone else in the league this term.Regardless of their lowly league position and their abject record against United, Wigan played the better football for much of the first half.In particular, Victor Moses caused the league leaders plenty of trouble, first intercepting Paul Scholes's pass and forcing Edwin van der Sar into action at the near post before his square pass found James McCarthy at the far post via Charles N'Zogbia's backheel, and once more Van der Sar spread himself well to make the stop.In the absence of Rio Ferdinand and Jonny Evans, Chris Smalling once again put in an assured performance at centre-back for alongside the ever-dependable Nemanja Vidic, giving plenty of hope to United and England fans alike. Each and every one of Wigan's seven first-half corners (to United's none) were cleared in authoritative manner.When United did break forward Rooney was always involved, and his canny give-and-go with Darren Fletcher set up Nani, only for the in-form winger to see his strike crash off the near post and across the face of goal.After the break Nani stepped his performance up a gear and had several chances to add his name to the scoresheet.He had one deflected effort saved by Al-Habsi at the near post before firing into the side netting. Once more he was denied by the Oman keeper, who spilled the shot from the edge of the box to the feet of Rooney. The England striker laid the ball off for Fletcher to strike, but again the effort as saved and Gary Caldwell completed the clearance.At one down Wigan were not completely out of the picture, as Maynor Figueroa tested Van der Sar's alertness from range and Moses fired high and wide from inside the box, but United were soon out of sight.Hernandez claimed his second when he headed down to Rooney in the centre circle and his strike partner slipped through a weighted pass for him to meet and go one-on-one with Al-Habsi before dispatching clinically into the bottom corner.Rooney then scored his fourth goal in as many league games when Michael Carrick's long clearance released substitute Berbatov down the left. With Caldwell the only defender, the Bulgarian squared to Rooney for the simplest of tap-ins.Fabio completed the rout just moments after replacing Nani with a neat finish at the far post from Fletcher's cross.With Wolves securing a vital win over Blackpool, a win over Liverpool for West Ham on Sunday will see Wigan end the weekend bottom of the table.