Cotton was named grand-final MVP for his performances across the three games, and Gleeson marvelled at the 24-year-old's game-three heroics.
"It's one of the best performances I've seen," Gleeson said of Cotton, whose tally included seven three-pointers.
"He was quick. He was shooting threes - he was dishing for dunks.
"Thank goodness he was playing for us. He carried us - to get that offence ticking over."
Cotton said his performance in front of 13,611 fans was still sinking in.
"If someone had told me that was going to happen, I wouldn't have believed them," Cotton said.
"It's a surreal feeling. Just knowing the ups and downs we went through this year - it's great.
"I've only been here a couple of months, but it's been a hell of a ride. And to end it like this is perfect."
Illawarra coach Rob Beveridge also described Cotton's performance as one of the best in NBL ranks.
"What an amazing player he is," Beveridge said.
"We've been blessed in this country to see players like him.
"He's making huge plays; he's getting to the rim.
"He's one of the quickest, most athletic, dynamic players I've gone up against. He is an NBA player, right there."
This season's title will be remembered as one of the most remarkable in Perth's history.
The Wildcats were languishing in last spot in December, and the club took a huge gamble when they axed import Jaron Johnson for a second time.
But the arrival of former NBA guard Cotton and the return from injury of Martin helped spark a fairytale revival.
The Wildcats swept Cairns 2-0 in the semi-finals, and the Hawks were simply no match for Perth in the best-of-five Championship series.
Star Wildcats forward Matt Knight missed game three because of concussion fears after a knock to his head last Wednesday.
Knight has a history of concussion issues, and will sit down with the club in coming weeks to discuss his future.
Hawks import Marvelle Harris scored eight points just a day after his father Marvin had died.
The Wildcats led 44-28 following three straight triples from Cotton in the second quarter.
But with Clarke unleashing his own magic from long range, the Hawks twice closed the gap to two points.
It ensured some nervy moments, but Cotton stepped up to the plate each time Illawarra challenged.
The win was a fitting way for Wildcats legend Shawn Redhage to bow out of the game.
"Not many guys get to go out with a Championship, so I'm proud of this team," Redhage said.
TOTAL NBL CHAMPIONSHIPS WON:
8 - Perth Wildcats
4 - Adelaide 36ers, Melbourne Tigers, New Zealand Breakers
3 - Canberra Cannons, Brisbane Bullets, Sydney Kings
2 - North Melbourne Giants, South East Melbourne Magic, St Kilda Saints
1 - Launceston Casino City, West Adelaide Bearcats, Illawarra Hawks, South Dragons
- AAP
