Opening lead: diamond king
In response to the artificial and strength-showing one-club opening, Chiaradia's one no trump showed four controls, counting the ace as two and the king as one. This response is also artificial. It was purely a coincidence that these controls included a stopper in the opponent's suit.
Later, South's four no-trump bid promised additional values and asked what features his partner held that had not been shown already. (North's bidding had thus far declared his ace and two kings and some strength in spades.) When North announced with his bid of five clubs that he also possessed some additional strength in that suit, namely the" king and jack, South felt completely justified in bidding his small slam.
Dummy's ace of diamonds won the opening lead and declarer discarded a spade. He led a spade to the 10, losing to West's jack. After ruffing the diamond return, South cashed the heart ace and spade ace and went to dummy with the heart king. He ruffed a spade and when the king dropped, North's queen was good for a club discard and the club finesse became unnecessary. However, the club finesse would have worked if need be, and the slam contract was an excellent one.
In fact, at the other table, the North-South pair for Holland bid to a grand slam. Against the same king-of-diamonds opening, this rather ambitious contract could have been made by a finesse in clubs and a squeeze against West in spades and diamonds. After ruffing out East's diamonds, declarer comes down to an end position like this:
[Queen of Spades]
[9 of Diamonds]
[King of Clubs]