Santini overhauled Bristol De Mai in the Grade Two Paddy Power Cotswold Chase at Cheltenham to enhance his Gold Cup claims.
The Nicky Henderson-trained horse was having just his second run of the season but he improved plenty from his narrow Sandown success by beating last year's Gold Cup third Bristol De Mai.
Nigel Twiston-Davies' grey had forged ahead again under Daryl Jacob jumping the last but Santini knuckled down up the hill to retake the lead in dramatic fashion.
The winning distance was three-and-a-half lengths at the line and with the Gold Cup another furlong in distance Santini certainly advertised that he has a chance in the Blue Riband on Saturday afternoon.
His jumping wasn't perfect on occasions, but Nico De Boinville gave him a great ride towards the head of affairs and it was no surprise to see Sky Bet cut him to 6-1 for the Gold Cup afterwards.
Henderson said: "It is one step forward but there is a long way to go. It was 200 per cent better (than Sandown) but to be fair we did cauterize him after that, but I don't think that had a lot to do with it - ours were just a bit fat.
"He can be a bit like that but this horse absolutely lives and thrives on work. The more you can get into him the better he becomes. He has always been the same.
"When you can't train him he goes the other way again. You have got to fire work at him. The more you do the better he gets. There is more to come.
"When you consider the race he ran in the RSA last year you have to say he likes the track. I don't say he dislikes Sandown, he was sloppy at Sandown. He wasn't wound up and I hadn't done a lot with him.
"The last three weeks he has just been doing that the whole way and I genuinely believe he can do that again."