(Photo taken from the official site)
Kamsky won against Nakamura (due to Black’s mistake in the middlegame which allowed White to get a huge advantage immediately), while Caruana drew. So, Kamsky leads the event with 6 points and Caruana and Dominguez are on 5.5 points.
Results of the 8th round
GM Grischuk Alexander 2779 ½ – ½ GM Caruana Fabiano 2774
GM Dominguez Perez Leinier 2723 1 – 0 GM Morozevich Alexander 2760
GM Topalov Veselin 2793 0 – 1 GM Bacrot Etienne 2725
GM Kamsky Gata 2741 1 – 0 GM Nakamura Hikaru 2775
GM Ponomariov Ruslan 2742 0 – 1 GM Kasimdzhanov Rustam 2699
GM Ivanchuk Vassily 2755 0 – 1 GM Svidler Peter 2769
Standings after the 8th round
1 GM Kamsky Gata 2741 USA 6
2 GM Dominguez Perez Leinier 2723 CUB 5½
3 GM Caruana Fabiano 2774 ITA 5½
4 GM Grischuk Alexander 2779 RUS 4½
5 GM Kasimdzhanov Rustam 2699 UZB 4
6 GM Ponomariov Ruslan 2742 UKR 4
7 GM Svidler Peter 2769 RUS 3½
8 GM Bacrot Etienne 2725 FRA 3½
9 GM Topalov Veselin 2793 BUL 3½
10 GM Morozevich Alexander 2760 RUS 3½
11 GM Nakamura Hikaru 2775 USA 3
12 GM Ivanchuk Vassily 2755 UKR 1½
Pairings of the 9th round
GM Svidler Peter 2769 – GM Grischuk Alexander 2779
GM Kasimdzhanov Rustam 2699 – GM Ivanchuk Vassily 2755
GM Nakamura Hikaru 2775 – GM Ponomariov Ruslan 2742
GM Bacrot Etienne 2725 – GM Kamsky Gata 2741
GM Morozevich Alexander 2760 – GM Topalov Veselin 2793
GM Caruana Fabiano 2774 – GM Dominguez Perez Leinier 2723
Nakamura playing the French Defense?! This has to be a big deviation from what he normally plays with the black pieces.
As a chess Instructor, what would you tell your students about Nakamura moving his bishop before a Knight and then moving his knight to the H file. Then he moved his kings bishop pawn and weakened his king. When Kamsky took the Knight on the H6 Naka had to take back and ended up with double pawns on the H file! Seems to me Kamsky obtained a strong advantage from the moves mentioned above.
I am sure Nakamura knew what he was doing, besides, the first 10 moves were theoretical. As for comments, you can see them in my annotated game (Kamsky-Nakamura) of that day. Everything, including where white got the advantage is explained there.