The following game was played between Sunil Weeramantry of Sri Lanka and a master from Andorra. The Andorran master's mistakes resulted in a quick victory for his Sri Lankan opponent. Sri Lanka was white and Andorra was black. Here I will provide my analysis of this fascinating game.
1. e4 d6
2. d4 Nf6
Black chooses to play the Pirc Defence. With this move order, it is expected that he will advance his king knight pawn and fianchetto his king bishop.
3. Nc3 g6
4. Bc4 Bg7
Black's third and fourth moves are as expected.
5. Qe2 0-0
White's fifth move is unusual. It is an aggressive move which signals that he intends to push his king pawn. Black's decision to castle here is a mistake. He should play Nc6 to fight for control of the centre. The decision to castle is premature. He should bring out his queen knight prior to castling.
6. e5 Nd7
White continues with the advance of the king pawn. Black retreats his knight but Nd7 blocks the light-squared bishop. He should move his knight to Ne8.
7. e6 fxe
8. Bxe6+ Kh8
9. h4 Nc6
White prepares to rip open the h-file. Black's move does nothing to prevent the opening of the h-file. Here he should play Nf6.
10. h5 Nxd4
White continues to advance on the h-file and black takes a pawn.
11. hxg Nf6
White ignores black's attack on his queen. He can do so because black's pawn is pinned and he threatens mate on the next move. Black finally defends with his king knight but it is too late.
12. Rxh7 Nxh7
Despite the presence of black's knight, white captures black's pawn and puts him in check. Black has to capture white's rook with his knight.
White puts his queen on the h-file so that he can checkmate on his next move. Unable to stop the mate, black resigns.
The Andorran master commits a number of mistakes. He castles prematurely, thereby encouraging white to continue the advance of his king pawn. He retreats his knight to a square where it blocks his light-squared bishop and he attempts to generate counterplay with his queen knight instead of using his king knight to prevent the opening of the h-file. This game illustrates that premature castling can be fatal.