Rhett Rachinski put the Flames ahead after just 64 seconds with what proved to be the lone goal of the first period, Tomas Nechala doubling Guildford’s advantage four minutes in to the second frame.
A powerplay goal from Kruise Reddick shortly after looked to have put the home side well on the way to victory as they led 3-0 after 40 minutes, but Coventry came back hard in the third period.
Blaze stalwart Brett Robinson four minutes in to the final frame before captain Jordan Pietrus converted on the powerplay to move the visitors within one.
Former Coventry forward Liam Stewart scored Guildford’s fourth but a quick fire double just 27 seconds apart saw the Blaze move level, Robinson scoring his second of the night before British defenceman David Clements scored unassisted.
With the two sides tied at 4-4 at the final buzzer, the game moved to overtime where Jesse Craige and John Dunbar combined after just 23 seconds to set up Brett Ferguson for the winner.