Lions head coach Warren Gatland has a simple thing to do today. He should reach for his contacts book, locate the name of Brian O'Driscoll, punch in his number and invite the warhorse Ireland centre to be Lions captain in Australia this summer.
O'Driscoll's performance in Cardiff on Saturday means that the debate is at an end. The other contenders are trailing far in the O'Driscoll slipstream.
As Wales flounder so, too, does Sam Warburton. He remains a solid citizen, valiant, steadfast but with a hollow look in his eyes, no longer the upbeat totem of a Grand Slam team.
Now if England were to triumph in Dublin on Sunday and carry on to nail their first Grand Slam in a decade, then Chris Robshaw's case would carry a certain weight. But well as the Harlequin has played, confounding the patronising view that he is somehow not an out-and-out No 7, he is still far from certain of making the 35 to 37-man cut as a player. Back-row is the Lions' strongest suit with high-grade operators in all four countries.
There are no such worries for Ireland's warrior prince. O'Driscoll has lost none of his class, none of his midfield magnetism, none of his potency or subtlety. He is spiky and deft in equal measure, dark as well as light, an attacking beacon as much as he is a defensive rock. He is a man for all shades.
He might, only might, have lost half-a-yard of pace but he more than compensates for that with his speed of thought. He is sharper than any around, able to see openings where others only see clutter, able to programme a way through or behind the most unforgiving of defences.
His behind-the-defensive-wall pass to Simon Zebo for Ireland's first try drew gasps of astonishment from a packed press room watching on TV from afar at Twickenham. Thereafter, O'Driscoll did as he had done so often and became the focal point of an Ireland team on the rampage.
It is not just what he does himself, it is what he inspires others to do. That is the mark of a true leader. If he is fit, he is the Lions No 13.
It is often said that nationality does not matter on a Lions tour as everyone becomes a Lion when they meet up. I think it does matter. O'Driscoll would be a perfect fit in that regard, a foil to the Anglo-Welsh management team, a representative of his country as much as he would be of the red shirt. The mix is important.
O'Driscoll is a star without the inclinations of a star. He is a figurehead without the ego, a leader of men without any attendant pomp. He is a class act, one that would set the tone and whom others would follow.
Get dialling, Warren. (© Daily Telegraph, London)