Altior was made to battle in the Betway Queen Mother Champion Chase but eventually prevailed in the day two showpiece at the Cheltenham Festival to extended his unbeaten record over obstacles to 18.
In doing so he moved level with the great staying hurdler Big Buck's - but the result looked far from certain for much of the home straight.
Nico de Boinville was content to follow Saint Calvados in the early throes, but the 4-11 favourite left his hind legs in the water jump and for the next few fences he jumped a bit too big.
Left in front at the third-last, De Boinville still looked confident, although the challengers were mounting up behind him, with Ruby Walsh angling second-favourite Min for a run.
However, it was Sceau Royal who nipped up his inside and hit the front approaching the last, as Min dropped away tamely.
On jumping the final fence Altior began to stay on, only for Politologue to appear on his outside to challenge, but Nicky Henderson's stable star, as is his wont, pulled a length and three-quarters clear.
It was a fourth Festival success for Altior after wins in the Supreme Novices' Hurdle, Arkle and this race last year.
De Boinville said: "What an absolute monster and aren't we lucky to be in an age where he's here. We should just celebrate him. He's a phenomenal athlete - he doesn't know how to lose."
Henderson said: "I was forgetting it was his 18th straight win. I was thinking about Winx and I thought that's totally irrelevant, 18. The whole team is what it's all about. They have been brilliant.
"He's a better horse on better ground, we've always said that, and he did get headed. But he very quickly found all that was needed. He's hugely talented, but very brave as well."