Sir Graham Henry says a Lions series victory would be an "astronomical" achievement which can further propel Warren Gatland into the All Black coaching frame.
Henry, the only man to have coached the All Blacks and British and Irish Lions, told the BBC: "He's one of the most experienced coaches in the world, he's had a long run with Wales and won a couple of Six Nations.
"He's been with the Lions for some time and done exceptionally well. The All Blacks are currently the world champions and ranked number one in the world.
"So to beat the All Blacks at home with a side which has had very little rugby together would be an astronomical achievement. Warren's done a great job in getting them all together and he's possibly a future All Blacks coach."
Henry initially described the Lions tour schedule as a suicide mission, a view accepted by many pundits. So while he brought a powerful side to New Zealand, Gatland has already beaten the odds by levelling the series in Wellington.