Iguodala produced his best performance in the series with 22 points and nine assists, while Stephen Curry also notched 33 points for the Golds.
"The thing I'm most happy about is that we didn't panic," Iguodala told reporters after the game.
"You go down 2-1, it kind of feels like the world's going to end, from the outside looking in. Fans are kind of panicking: We can't lose, we can't lose.' But we kept our composure, did what we had to do."
The two sides will meet for Game Five on Tuesday in Los Angeles.