6 dans bloody game

Today I saw an interesting game in KGS between two 6 dans. From the very beginning, each player settled an are of influence and black was the first one to attack. It wasn't long before black had already reduced a big deal of white's zone, so now it was the turn of the white player to invade black's area of influence.

The resulting invasion was something rather spectacular, with a big white dragon trapped between a couple of black groups as seen in the image above. But, all of a sudden, white found a tesuji with unforeseen consequences. Can you find the first move?

Now the game turned into an all-in-all game, whoever won this capturing race would win the game. Let's take a look at the board after having placed the appropiate stones:

The next move by black was S1, followed by W P1, B deffenses atari, W P11 in order to reduce black's liberties, Black S3 was very polemichal and white deffended the atari and plays the vital point at T2. As you can see by the sequence, white started reducing some of the liberties of black and the latter only has 2 liberties remaining against 4 for white.

Is there any possible sequence which would have given the victory to black?

If you wanto know the answer and watch the whole game, check the "continue reading"

Here you have the game loaded in Eidogo:

Unfortunatelly, black didn't spot this combination during the game and gave up short after being killed. During the review, he played S3 earlier but the sequence was left unconcluded, we thereby suppose this was the correct sequence.

Please, if you find a better sequence for any player, let me know and I'll try to add it to the sgf file.