I Am Maximus, ridden by Paul Townend, has won the Grand National Credit : Owen Humphreys/PA There is no greater accolade than being an Aintree great and I Am Maximus cemented his position as one of the very best to grace this famous corner of Liverpool as he won the Grand National for the second time in three years. The 178th National was one of the most eventful in recent times, a real throwback, as the winner survived mayhem to lead home a one-two-four for owner JP McManus . He beat Iroko by 2½ lengths with Jordans – the only placed horse not carrying the green and gold silks of McManus – in third and Johnnywho fourth. So it is two wins in three years for I Am Maximum, sandwiching his gallant second a year ago. It will be 12 months before he gets a chance to equal Red Rum’s three wins in the 1970s, but there are likenesses; he became the first horse since the immortal “Rummy” to carry top weight to victory and the first since him to regain the race.…