WednesdayReading     2 - 2     ChelseaFulham    3 - 1     West Ham Arsenal     2 - 2     LiverpoolNorwich City     1 - 1     Tottenham Everton     2 - 1     West BromLONDON - Manchester United manager Alex Ferguson has challenged his three main strikers to each reach 20 goals this season as the Old Trafford club aim for a trophy treble.United moved seven points clear at the top of the Premier League table with a 2-1 win at home to Southampton on Wednesday.They have an FA Cup fifth round tie to come against Reading and also face Real Madrid in the Uefa Champions League last 16 next month.Rooney scored twice against the Saints to take his tally for the season to 12 goals, while Robin van Persie has scored 22 in all competitions and Javier Hernandez has managed 14.Ferguson believes that if Rooney and Hernandez can join Van Persie in passing the 20-goal mark it will have a key impact on United’s chances of silverware."Wayne scored (in the 4-1 win over Fulham) on Saturday too and if Chicharito, Wayne and Robin give us over 20 goals each we’re in business,” Ferguson said."If you look at it my experience of this club and going for championships, there’s always a game where you say we were a bit lucky and (the win against Southampton) was one of these nights."Winning is the name of the game at this stage of the season.”Southampton striker Jay Rodriguez opened the scoring after just two minutes at Old Trafford when United goalkeeper David de Gea failed to reach England midfielder Michael Carrick’s back-pass.But Rooney struck twice, driving in from a Shinji Kagawa pass and finishing from Patrice Evra’s header, with his ninth goal in nine games securing victory for United.