The reigning premiers had to draw on all their reserves to beat the flag favourites, fighting back from 23 points down seven minutes into the third term to clinch a 15.14 (104) to 13.16 (94) triumph.
Despite playing below their best, the Hawks were able to wrestle back the momentum and held on grimly as the Swans kept coming to notch a crucial 13th win for the season.
"Our resilience and perseverance just to hang in there when things weren't working out for us too well early in the third quarter (was important) to turn the game around," Clarkson said.
"I think from that point in time we kicked seven goals for the last 15 or 20 minutes of the third quarter.
"We go from a 20-point deficit or thereabouts to a 10-point or thereabouts lead at three-quarter time – that's great resilience.
"I'm sure our players will get a lot of confidence out of being able to cope with that sort of situation."
The Hawks' victory - which moved them to within 0.8 per cent of the ladder-leading Swans - was all the more impressive given their defence was undersized and understrength without Brian Lake and Matt Spangher.
At one stage it looked as though the Hawks' defence might buckle under the combined threat of Lance Franklin, Kurt Tippett and Adam Goodes, who booted nine goals between them.
In both meetings this year, Hawthorn has been troubled by the Swans' tall forwards but unlike in round eight, this time the Hawks found a way to win.
"They're formidable opponents those big fellas up forward and we've just got to cope as best we can," Clarkson said.
"The midfield battle – I know that both sides have got potent forward lines – we managed to square-off pretty easily through the middle of the ground and that was really important."
Clarkson said the Hawks had faith in Ryan Schoenmakers, the returning Josh Gibson, Ben Stratton and Angus Litherland to get the job done.
"That depth is really important for us but we're not just banking on those players to be there for us," he said.
"We've got good depth at our club and players that can come in and perform roles.
"When they've got trust in themselves and trust in their teammates then you can get results like we've got tonight.
"That's what was really pleasing. We didn't play our greatest footy but we found a way to get the job done."
Although Clarkson was unwilling to look beyond next weekend's clash against the Western Bulldogs at Aurora Stadium, the two-time premiership coach acknowledged how crucial Saturday night's win was for the Hawks.
"It's really tight at the top. We just can't drop off. Tonight's game was really important for us because had we lost, Sydney would have gone two games clear of us," he said.
"That keeps us in the mix. We want to get as high as we can on the ladder and it's as simple as that so we focus no further than the Western Bulldogs next week."
Clarkson confirmed midfielder Brad Sewell (hamstring) would be "touch and go" to be available to take on the Dogs.
