Less than a minute later, Jonathan Huberdeau was sprung on a breakaway but Blackwood got his toe to the post to deny his backhand/forehand deke.
Andrew Mangiapane had a breakaway later in the frame with under five to go but his shot was swallowed up by the Sharks netminder.
Calgary went 0-for-2 on the powerplay in the first (and were blanked on five attempts in the tilt) but had two great looks on the second advantage: Blackwood making a big stop on Yegor Sharangovich’s one-timer from the slot on the zone entry, then Backlund ripping a one-timer off the post from the right faceoff dot.
The Sharks got two goals courtesy of Mikael Granlund and Justin Bailey in the first 7:50 of the middle stanza, both following giveaways deep in the Flames zone.
The visitors then made it 3-0 after a weird play where Wolf appeared to stop a puck during a net-front scramble. However, the whistle went 34 seconds later and it was reviewed, the puck shown to have crossed the goal-line, the goal credited to Luke Kunin.
The Flames got back within one with 19.4 seconds left, Backlund circling behind the net and out near the right faceoff circle and wiring one past Blackwood.
Just after the puck crossed, Calen Addison had thrown Mangiapane into his goalie and San Jose challenged citing goaltender interference.
After a long review, the goal stood giving Calgary a powerplay for the final ticks and the beginning of the third.
