His performance, when beating Beef Or Salmon by 17 lengths in the Betfair 'Chase at Haydock on Saturday, simply took the breath away.
The relevant horse in the contest was third placed L'Ami, beaten 18 lengths, having very much run to his best, one suspects.
The same L'Ami was fourth behind War Of Attrition in the Gold Cup in March, beaten a total of ten and a quarter lengths.
Ruby Walsh's behaviour, in the aftermath of Kauto Star's display, told us most of what we needed to know.
My experience of Walsh is that he is a realist, totally, and not prone to over-rating horses. He just doesn't get carried away and when you see him start to smile half way up the run in and watch that smile broaden as wide as the Grand Canyon then you know that here is a man who has just enjoyed the ultimate, almost, adrenalin rush.
The word almost is used advisedly, because the ultimate rush will surely only come with victory in the Gold Cup, which, you'd imagine, Walsh absolutely craves.
Kauto Star will be seven next March and that's, arguably, the ideal age. Imperial Call was seven when he won, so was Kicking King, War Of Attrition and Best Mate, when landing the first of three successes.
Can you find a hole in Kauto Star after Saturday? Well he jumped brilliantly, travelled sweetly, got the three miles standing on his head and quickened clear when asked only to do the minimum. Short answer-no.
Yesterday, he was a top-priced 5-4 for the King George at Kempton and that looks reasonable, with War Of Attrition set to stay at home.
THE jury remains firmly out on Brave Inca, following his return to racing in the Morgiana Hurdle at Punchestown on Sunday.
I wrote here last week that the race might tell us whether the horse, who has got into more fights than Bernard Dunne, retains all his enthusiasm.
It was rather inconclusive and we will have to see Brave Inca again before any sort of conclusions can be reached.
I don't know about you, but I was pretty impressed with Iktitaf, notwithstanding the fact he had a big fitness advantage over his three rivals.
The only reason, at least to my eyes, he came off the bridle was because of the manner in which the last was negotiated.
Course commentator, Dessie Scahill, said he jumped it like a fence and could hardly have got it more right. Iktitaf landed flat-footed and then had to be bustled along by Paul Carberry.
If he had winged that flight, he would have been away and clear and value for a few more lengths!
There are so many imponderables in the Champion Hurdle right now that an ante-post wager would be particularly hazardous.
Indeed, the news last night that both Macs Joy and Harchibald have suffered minor setbacks, and miss Saturday's Fighting Fifth Hurdle at Newcastle, only further complicates the situation.
HEARD a couple of the press whippersnappers say at Cork on Sunday it was the worst day they had ever been at a race meeting. Easily known they never donned the trusty rubber boots at point-to-points in the good old days.
It was, of course, bad and some achievement to get through the day. Conor O'Dwyer summed it up best when, returning after a race covered in mud, remarked: "what else would you be doing on a Sunday.'' At times you really do need a sense of humour in this game.
A lot of the bookmakers gave up, some because they were afraid their costly equipment would be blown over and damaged in the wind. Indeed, only 13 of that hardy group were still standing at day's end.
Anyway, it was great to see Cork beat the elements and proved it is a track which can race in the winter.
The weather on the lead-in was bad and atrocious on the day. But there never seemed to be a doubt about the meeting and that's encouraging.
It is also a track, I think, which rides best when conditions are actually testing. Cork races again on December 10 and twice in January and, hopefully, will be rewarded with far better weather than last Sunday.