Silfverberg gave the Ducks a 1-0 lead 12 seconds into the second period after Adam Henrique won the opening face-off. Silfverberg took a backhand pass from Hampus Lindholm and scored on a one-timer from the left circle.
"They had some pushes throughout the game, but I definitely think we created more than enough to score more than one goal tonight," Silfverberg said.
The Flames tied it 1-1 when Stone scored at 15:32 of the second. Stone, who was a healthy scratch the previous four games, beat Gibson with a one-timer from above the slot.
"It felt good to contribute," Stone said. "It's been a while since I've done that, so to get in there and get rewarded was nice."
The teams combined for two shots on goal through the game's first 10 minutes, but one got past Gibson before he managed to squeeze the puck between his skates to keep it from crossing the goal line.
Gibson made another point-blank save on Calgary's third shot of the game by Michael Frolik at 10:58 of the first period, using his outstretched right pad to turn away the shot.
"That is a regular occurrence for him," Ducks coach Dallas Eakins said of Gibson. "That is the expectation that he has on himself, and it's always great when a young man like that has those expectations."