I was trying to wait 24 hours!
Unfortunately it seems chessgames doesn't have this game in their database so here is the PGN for the game:
White has a clear target on h7 but black just played Rd7 and is threatening to double up on the d file and penetrate. It's impossible to block up the d file. For instance:
1. Bd4 Rhd8 2. c3 Bxb3 3. axb3 c5! 4. Bxc5 Rd2 and black's rooks are out of control.
Even declining the sac doesn't work:
1. Bd4 Rhd8 2. c3 Bxc3 3. axb3 c5 4. Be3 Rd2! when black will pick up at least two more pawns for the exchange and end up 4 pawns for a piece in an endgame where white will get to try to grovel his way to a draw.
If white just tries to get along with his play on the h file:
1. Kg3 Bxb3 2. axb3 Rhd8 3. Rh1 Kg8 4. Nc3 and it looks difficult for white do anything. His knight can't move or black penetrates down the d file and there's no targets for his rook/bishop to go for even if black just shuffles.
So white comes up with a super creative winning attempt:
Now: 1. c4 Rd8 2. Nf4 is practically winning for white as his bishops will zip all over the board and black has no penetration squares at all on the d file.
Black trying to give the bishop a flight square doesn't work either:
1. c4 Ke7 2. Nf4 Bf7 3. Nd5+
Black's only chance is what he played:
1. c4 b5 but then the tons of targets for white along with black's inability to penetrate on the d file spelled a quick end for him as Nisipeanu clearly illustrated.
Just an amazing position and idea. 1. c4!! is a move I probably wouldn't even really consider on 'principle' alone. It looks so ugly but it's just so good.