By Samuel Meade If Liverpool want to extend their lead over Manchester City to five points on Saturday afternoon they’ll have to do something they’ve never done – win at the Gtech Community Stadium. The Reds will head to west London to take on Brentford, who have proved a tough nut to crack since their promotion. Liverpool have won at more Premier League grounds than any other club but have yet to leave the Bees’ home with all three points. In Brentford’s debut campaign, they held Jurgen Klopp’s side in an entertaining six-goal thriller that ended with a late equaliser. Last term, Liverpool we…