The wrong way to conquer the pawn on c6. 13...Qc7 is better. After 1 4.g5 Black can return the piece with 14...0-0.

15.c7! The refutation.

White is completely winning, which he did in the end.

“I feel this man had to be the World Champion and nothing would stop him. It was a foregone conclusion. His career took a rather roundabout course but everything was already mapped out!” — Vladimir Kramnik

For a change, here we see Black planting a colossal knight in the center. This is by far less common. Funnily enough, this example also features another structure than a Hedgehog or a Sicilian. The basis remains the same though: the e-file is opened while the white king is still in the middle. It was Karpov who introduced this concept (starting with 10...Re8) against Kortchnoi in the famous Baguio match.

13.exd4
Apparently, Leitao didn't know his classics. In a later game against Mecking, Leitao (just like Karpov) decided to refuse the sacrifice with 13.Qb1.

17...Qxb3 18.Qxb3 cxb3 was a safe alternative, where Black just keeps his extra b-pawn.

Now Black's weakened kingside gives White counterchances.

Finally.