Johnny Sexton hails Ireland’s ‘incredible’ defence under Andy Farrell

• Win over England was Farrell’s first Twickenham visit since sacking• ‘Hopefully we can have good crack at next World Cup,’ says SextonIreland were forced to cancel their planned homecoming in Dublin on Sunday because of the adverse weather but it will take more than that to dampen the celebrations after securing only a third grand slam in their history. For the defence coach, Andy Farrell, the manner in which it was achieved makes it all the sweeter.A third Six Nations title under Joe Schmidt had already been secured but a first Ireland away win against England since 2010 ensured the cl…