Petrosian on the Attack: Converting the Advantage

A couple days ago, we left off with this chess position:

Rather than respond to the attack on his g2-pawn, Petrosian played 35.Kd4(!). This move does two things: It opens a discovered attack on the c7-square, threatening Rc7+, and it prepares Ke5, centralizing the king and approaching Black's vulnerable pawns on e6 and h7. Black cannot allow White's rook to invade the 7th rank. For example, 35...Rxg2 36.Rc7+ Kd8 37.Rxh7, followed by Ke5, will win quickly for White. This is yet another example of ignoring the opponent's threat by creating your own equal or stronger threat! It is also a good reminder to continue to seek aggressive, forcing moves in the endgame.

Black had to defend the seventh rank with 35...Kd7. "White's king, knight and rook rapidly threaten to overwhelm the black king in the center. Black's bishop and rook are complete bystanders" - Pritchett. Play continued 36.g3 Bb4 37.Ke5 Rh5+ 38.Kf6 Be7+ 39.Kg7 e5, bringing up the following position:

The end is drawing near. Can you see how Petrosian continued the attack?