GEELONG skipper Joel Selwood thought the Cats had lost as Hawthorn's Isaac Smith kicked for goal to win the game after the siren on Friday night.

"I couldn't believe that it came down to that," Selwood said.

Watching from in front of where Smith took the kick, the Cats' star thought the 27-year-old Hawk's kick was straight enough to give the Hawks passage into a home preliminary final and leave the Cats in a sudden death semi-final.

"I had that moment where I thought we're coming back next week to play the Bulldogs," Selwood said.

Smith misses as Cats edge Hawks in thriller

The triple premiership Cat was also cursing the fact Smith even had the ball in his hands, given that less than a minute earlier it had been bumbling around the Cats' goal line.

"I think if we had our time again we would play it a little bit differently but in the moment they are things we have got to learn from," Selwood said.

He stated the obvious, that teammate Steven Motlop could have chosen a different option than shooting for goal from an impossible angle, which led to a point and the Hawks' kick-in, but he said the kick-in should have been defended better too.

"We just had to defend better when it got kicked in and we didn't do it quite as well as we would have liked," Selwood said.

Having got lucky, and with moments such as Motlop's late third-quarter goal that gave the Cats a lead into the final break fading into the background, Selwood was able to be philosophical.

He said the half-dozen players playing their first final would benefit from the experience with the epic nature of the contest a good reminder to everyone that "doing the simple things for longer" is what wins finals.

It was the third time in the past 18 encounters between the two teams that the game had been decided by a kick after the siren with the Cats victorious each time.

It was also Josh Cowan's 13th win from 13 games and a win for Dan Menzel in his first final for five years after four knee reconstructions, just the second win the Cats have managed in their seven finals since 2011.

And a chance for Selwood to thank the heavens he wasn't playing again this Friday after victory was snatched from the jaws of defeat.

"To get out of jail and have our moment to get through, we're pretty thankful," Selwood said.