O'Neal then came up with a block on the defensive side of the floor when Monta Ellis drove the lane with 13.9 seconds left.
Curry brought the ball up the floor on the ensuing possession, shook Calderon and buried the jumper to give the Warriors the win.
Curry finished with 23 points and 10 assists, while fellow backcourt mate Klay Thompson poured in a team-high 27 points in the win. O'Neal had 20 points with eight rebounds for Golden State, who played without big men David Lee and Andrew Bogut.
Lee missed his third straight game with a strained hamstring and Bogut missed his second straight tilt with a bruised groin/pelvis.
Dirk Nowitzki deposited a game-high 33 points with 11 rebounds and Ellis netted 27 points in the setback.
Dallas dropped 1/2 game to ninth in the Western Conference standings behind Phoenix and Memphis.