The Seahawks were the first side to notch points in the encounter, with the trusty Steven Hauschka producing a field goal from 20 yards out from the post.
Neither side seemed keen to open up in the first quarter as they settled for an opening six-point affair, with Brandon McManus responding for the Broncos with a 24-yard field goal to leave things at 3-3 going into the second.
The Hawks made the most of the second quarter thanks to some superb technique from Russell Wilson, who produced a 39-yard loft to set Ricardo Lockette on his way, before Hauschka kicked to make it 10-3.
Wilson produced again right before the half came to an end as he threw adroitly from five yards to Marshawn Lynch, moving the scores to 17-3 at the break.
Despite a poor third quarter in which neither side was able to register, the Broncos were able to establish a tense finish as a Lynch rush saw Denver handed penalty points, before Peyton Manning converted a short pass to play in Julius Thomas, leaving his side within a touchdown of grabbing victory.
Following a drive of five plays and 25 yards, the Seahawks looked to secure their victory, with the immovable Hauschka kicking from 28 yards to make it 20-12 going into the final minute.
Manning produced the goods in the final few seconds as he threw for Jacob Tamme, before also finding Thomas for a two-point conversion to level the scores and take things to overtime.
However, Seattle showed that they weren't prepared to let the game slip any further having seemingly let the Broncos back in, with Lynch producing a six-yard rush after great work from Percy Harvin to grab a 26-20 OT win.