The Clash Between 2 World Chess Champions :GM\Ponomariov Beats GM\Kramnik In Dortmund 2010

The above endgame resulted from a very exciting game and powerful play by GM\Ponomariov against GM\Kramnik in their encounter (round 2) in Sparkassen GM Tournament (Dortmund 2010).How should white proceed in the above diagram ?
Source of the event:http://www.sparkassen-chess-meeting.de/2010/
Source of the photo:http://www.sparkassen-chess-meeting.de/2010/fotos/runde-2.html by Georgios Souleidis
The diagram is created by :Chessup.net (http://tinyurl.com/34y4wcq)

The Chess Genius GM\Gata Kamsky Masterpiece !

Gata Kamsky was born June 2nd, 1974 in Siberia. After beginning his chess career in Russia, winning two USSR Junior Championships, Kamsky relocated to the United States in 1989. In July 1990 he became the youngest player ever to be rated in FIDE's world top ten. After a short while spent adjusting to this level of opposition, Kamsky scored some major tournament triumphs, including the U.S. Championship of 1991, clear first at Las Palmas 1994, and shared first in 1995 at Dos Hermanas. In 2010 he won the U.S. Championship once again...(http://www.chessgames.com/perl/chessplayer?pid=15874)
In the above diagram GM\Gata Kamsky finished the game in 7 moves ...Could you figure it out ?
Source of the photo:https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsucntLj93eNOBLwOxoo4OsBEEBGy0kcN8Aer8b1RjbCdHpSS85jwUy47Xx9-fUia5K4kmYg_5P6awQ-VFAM-f-grpvXd2o6we5BrHCW7ILAiSIc-ymsRTMkaYp8T9OGKwhjs-q1F8OmMH/s320/kamsky.jpg
Diagram created by Chessup.net
(http://tinyurl.com/33qod7c)