The Spaniard has a tremendous swing and a new grip appears to have helped him to overcome some problems with putting that had been holding him back.
Victory was something of a knee-trembler in the end, with Fernandez-Castano taking six at the par four last, but he had effectively clinched his seventh European Tour title with a glorious chip-in at 17.
He now looks a very good bet to make his Ryder Cup debut next year at Gleneagles, and he would be a great weapon for captain Paul McGinley.
Another man hoping to be there is Peter Hanson, whose title defence got off to a bad start in Shanghai but finished with an excellent 63.
The Swede put his superb final round down to a desire to impress McGinley, his playing partner, and that’s exactly the attitude the Irishman will want in his team.
Also closing strongly at the same tournament were joint runners-up Francesco Molinari – when he is hot he is red-hot – and Thongchai Jaidee, who outshone most of his younger opponents.
For Rory McIlroy, who finished 10 shots adrift, it was unremarkable, but I have heard the former world No1 is hitting well again. McIlroy said as much after beating Tiger Woods in their exhibition match yesterday, and his optimism is a good sign.
With another event in China this week, the WGC-HSBC Champions, I’ll be interested to see how Paul Casey gets on. The Englishman played well in Shanghai and also impressed me hugely at the Seve Trophy. Thomas Bjorn is also playing fantastically, and I wouldn’t rule out Fernandez-Castano making it two in a row.
Sam Torrance OBE is a multiple Ryder Cup-winning golfer and media commentator. Follow him on Twitter @torrancesam