Gata Kamsky is famous for his excellent endgame technique, and he demonstrated it to win the first game of his match against the young Russian GM Ian Nepomniachtchi:
Kamsky – Nepomniachtchi, 2011 World Cup
White to move
Black is down a pawn, but he appears to maintain some sort of equilibrium because he defends both kingside pawns with the king, and the rook attacks the pawn on g2, making it more difficult for White to advance the king. But it turns out that because the position of the Black rook is passive - White wins rather easily.
40. Kg3 Zugzwang! Either Black king or his rook have to move. Kg7 This abandons the e6 square, so White can attack e5 pawn from the 6th rank.
(Moving the rook does not help either 40... Ra1 (no longer attacking g2) 41. Kg4! a2 42. Kg5 Ke7 43. Ra7+ Ke6 44. Kxg6 Rg1 45. Rxa2 +-)
41. Re6! Re2 42. Rxe5 a2 43. Ra5
After some move by Black, White can play h5 (if gxh5, then Rxh5), and with two connected pawns, the win is trivial:
For example 47… Kf6 48. h5 gxh5+ 49. Rxh5
This is a win according to tablebase: http://www.k4it.de/index.php?topic=egtb&lang=en
Replay the game here: http://www.chessgames.com/perl/chessgame?gid=1633762